Chelsea's use of the loan system is well-known by now, with the Blues having attracted both praise and criticism for the way in which they have sent players to other clubs for short spells over the last few years.
And while the infamous 'loan army' is used against the Stamford Bridge outfit on a regular basis, a look beneath the surface suggests that is working in west London.
In terms of young players, loan moves tend to form a key part of their development, and it is telling just how many of the Blues' academy prospects of recent times have gone onto play international football while either establishing themselves in the Chelsea first team or being sold for a huge profit.
More established players can benefit too, with loan spells working largely as shop windows for the individuals to prove they are worthy of being brought in a on a permanent basis by a different team.
Chelsea's use of the loan system meant they were able to record a net profit in terms of transfer fees in the summer of 2021, despite spending £97.5 million ($136m) on Romelu Lukaku, and now other clubs, including Manchester City, are following a similar model.
Of course, not everything worked out in Chelsea's favour. Kevin De Bruyne, Mohamed Salah and Lukaku himself were all sold by the club following spells out on loan, only to go onto become some of the best players in the world.
So how did it all come about, and could anything have been done differently? Goal spoke exclusively to Eddie Newton, Chelsea's former loan technical coach and mastemind of the system, to find out:
Goal: Eddie, tell us how the loan system started when you were brought in...
Newton: "It was up and running but it wasn’t a developed system. It was (ex-Chelsea technical director) Michael Emenalo’s brainchild basically. He brought me into his office and said, ‘Look, Rafa [Benitez] is a bit worried about having you because you were with the last manager (Roberto Di Matteo)’.
"So I wasn’t going to be with him in the first-team, but he had another job for me to develop and run the loan programme. He said we had too many young players who were too good for the Under-23s, but not good enough for the first team.
"We needed to send them away on loan, but we needed to do it better than before. We didn’t know enough about these guys away on loan. He gave me a blueprint and then I built it. We kept meeting every so often, and he said he would get me what I needed to make it work.
"The department began with just me and an analyst. We were working and going to watch games. Then, the list of players on my rota was getting too big and I couldn’t do it anymore.
"I told Emenalo that I needed to build a proper department, so I hired Paulo Ferriera next. He lived around the corner, had just retired and was good with languages, so we agreed he was perfect. We also got another analyst.
"Then we brought in Tore Andre Flo. We had goalkeepers on loan, so we needed Christophe Lollichon on board. We had an unbelievable team of coaches who travelled all over Europe to get feedback from managers and technical directors.
"It showed the players that Chelsea cared about them and were not just doing it for getting them off the wage bill. Many loans went well, others didn’t, but the ones that didn’t we visited more. We looked for ways to help the club manager.
"We developed the feedback we gave players and improved our organisation with other clubs. When Michael went, I would get involved in loan negotiations before it went onto Marina [Granovskaia]. It was something we built and that I was really proud of by the end.
"We built a world-class programme that I know a lot of other people are copying today. A lot of clubs came to us and asked us for a little bit of help, we helped them up their game and that’s fine. You can only have the secret for a little bit!"
Goal: You have to admit that your loan system was pretty unpopular at first...
EN: "It was normal. Michael wanted to go out and defend it, but the club wanted to keep it quiet. I don’t know why, but Michael wanted to defend Chelsea’s approach. He wanted to tell people it is working, but maybe not in the way people wanted it to work.
"I think a lot of people wanted us to loan these guys out and bring them into the first team one or two seasons later, but that was impossible. Utterly impossible.
"The clubs of the magnitude and pressure of Chelsea, Manchester United and all the big clubs in the world see that most young players can't make that jump right away.
"People like Mason Mount have done it now, but that’s because the loan programme became so developed alongside that work in the academy to allow it. The processes were easier for him moving from U23s to loan in senior football and then learning how to come back to the club to take his opportunity.
"It’s also down to the manager at the time. If the manager is not accepting of the younger player, then it doesn’t matter how good the loan programme is. A new manager could just sign a player for £50m, meaning it wouldn’t matter what we do.
"We still had to use this loan programme to better these players in the meantime though, and that’s exactly what we did. People in the football world quickly realised it was a fantastic financial tool for the club.
"Taking players of the wage bill, then selling them and often for more than we brought them in for. We were making a profit and developing players. It became the business tool for the football club."
Goal: Did it frustrate you looking at what happened to Salah, De Bruyne and Lukaku?
EN: "For me, I think Salah and De Bruyne wasn’t about talent. It was a personality clash [with Jose Mourinho]. I just didn’t think it was working at the time.
"I think they were more than good enough, but it was the manager who didn’t see eye-to-eye with them, so it wasn’t going to work.
"For Lukaku, he wasn’t ready at the time, and I don’t care what anyone says.
"He just wasn’t ready to be the main No.9 up front and carry that platform like Didier [Drogba]. He was always going to be compared to Didier and it wasn’t fair to him at that time.
"It was different situations for different players."
Goal: You also coached Lukaku when Chelsea won the Champions League in 2012?
EN: "He was a great kid with bundles of enthusiasm who wanted to impress. He was sometimes too desperate to impress that it went against him.
"I think he needed to come out of Chelsea and learn his craft elsewhere, which he did on loan at West Brom. My former team-mate Steve Clarke was looking after him.
"It was well documented and he will say it himself: he had the power and pace, and when he was younger he got away with blowing people away with his physicality, outrunning people in behind and scoring that goal.
"When he got to the top level, he couldn’t do it as much anymore. He hadn’t developed how to play with his back to goal. Every time the ball came to him, a defender would get tight and it would bounce off him. He gave it away a lot and it was frustrating.
"That’s why at Chelsea it would have been hard for him, because there was an expectation on him to hold up the ball, find the players then get back in the box to finish. That’s what Didier did and it left massive pressure. It was better to go away and develop it at West Brom.
"Steve was working on that with him and we agreed on having that as an aim. It was the same at Everton, speaking with [Roberto] Martinez. He got better, but he still needed to improve with back to goal and his movement. I would visit him and show him footage of his performances.
"I was showing him where to improve and what to do. In combination with working with the club coaching staff and the external support of the loan group, it helped him a lot.
"He got to Manchester United, didn’t take off as he would have hoped, but Antonio Conte had him at Inter. He was a pain for Lukaku and forced him to complete the journey with his back to goal. He worked tirelessly with him until he got his just rewards. It was a major factor on why he didn’t establish himself at the highest level earlier.
"He is now back at Chelsea, more mature and a senior player who can play with his back to goal and score. He is now ready to complete that journey and fair play to him. A lot of hard work went into where he is now."
Goal: What were your favourite moments involving loanees?
EN: "De Bruyne, Lukaku and Salah all had amazing games. I remember watching Salah versus Juventus away, and they (Fiorentina) were up against it, but he scored a beautiful goal on the counterattack, going past players and hitting it into the top corner.
"It was an incredible, incredible goal. I was in the Juventus section and I almost got up and celebrated it!
"We spoke about people not understanding the loan programme at the start, but the players didn’t either. After a season or two, they were coming to me and saying they get it now and appreciate it. The agents and parents' feedback started coming and it was positive. These were their careers that we were helping. I know they all wanted to play for Chelsea, but not everyone can.
"I was just being honest with them and they appreciated that honesty. The club did a lot for these players."
Goal: How is Thomas Tuchel going to use the loan system?
EN: "From what I hear at Chelsea at the moment, Tuchel is open to different things. He is a good guy, a good manager and is open to listening to different things. He will work with the youngsters coming in. It’s not just about working with the senior players.
"He’s from the German system, which is all about working with the young coach and young player. So he understands it. As well as that winning mentality, he understands development.
"No disrespect to any manager before, but Chelsea now have a manager who understands both sides of the coin. He knows he has to win titles, win matches and make tough decisions, but he also knows that there has to be a development space for these players.
"He will be getting the reports from the loan department, academy and have young boys training with the first team. He will understand it.
"He has a massive support system at Chelsea. If you utilise it properly as a manager then it is a wealth of information, so you have so many things to deal with. All the players coming through, doing well and he will see some doing well in training.
"It is up to him to make his mind up to develop his squad from there. I am really pleased for Trevoh [Chalobah], for example. I know his brother well and watched him a bit too. I worked with Mason Mount, Tammy Abraham, Reece James and Fikayo Tomori too, so I am pleased for all the boys.
"You could get frustrated at times because they were in a rush to get to where they wanted to. I was like that when I was a young player so I understood it. Their belief in their ability was very high, which helped them achieve what they achieved.
"I think Billy Gilmour will do well later in the season at Norwich. I really rate the boy, he did well at Chelsea when he came in. It will be interesting to watch him develop over time at Norwich."
Goal: You left Chelsea in quiet circumstances, what happened?
EN: "It was a bit difficult. I was being put on Frank [Lampard's] staff to be that senior guy, because it was quite a young staffing group. Chelsea wanted me to be that senior one for them, but it didn’t pan out and Frank wanted to go in a different direction.
"It became difficult and they decided to put me between loans and scouting, but it wasn’t for me anymore because I had been there and done it. Then came the opportunity to work at Trabzonspor, which I was a bit iffy about at first, to be honest.
"They had a Turkish coach they liked a lot but wanted me to look after their non-Turkish players. In the end, I asked Chelsea for permission to go and speak to their manager, and he wanted me there. It was great when I went there.
"We were competing for the league and went close. We got a few draws towards the end and it is very emotionally driven in Turkey. It’s emotive anywhere in football, but my god Turkey is emotive. With two games to go, the president sacked the manager!
"I was dumbfounded to be honest. There was no need in my opinion. It happened and the president rang me up and said the manager is sacked and you’re taking over tomorrow. But you must win both of the last two games.
"Fortunately, we won the first to finish second and the next one to win the cup final. I enjoyed it immensely. The president then took me on as the full-time manager over the summer. Unfortunately, the side I was then working with was dismantled.
"We lost five or six senior players. The president didn’t have real control over the transfers coming in and the players weren’t good enough coming in I thought.
"I did my best with those players and tried to develop some young players, but it was very difficult and at week seven, he sacked me as well. Unfortunately, we couldn’t build on what we started.
"We were expected to build something again from nothing. It was a difficult baptism of fire in management but you learn. It was a learning curve to understand that market and how they go about things. I will know better for next time."