Granit Xhaka raved about the qualities new signing Thomas Partey will bring into Mikel Arteta's Arsenal team.
Partey joined the Gunners from Atletico Madrid after they matched his £45 million release clause on the European transfer deadline day this month.
On Saturday, the Ghana international made his Premier League debut against Manchester City after replacing Xhaka as an 83rd-minute substitute.
Although Partey's arrival provides more competition in the midfield, Xhaka believes the 27-year-old would improve Arsenal squad with his experience and mentality.
"He will be the guy who is important for me and as well for the team. Everyone in the club can be happy because he has great quality," Xhaka told the club website.
"He will bring a good mentality, a good balance in our game because this is what we need a bit more: the mentality to win.
"He played at Atletico Madrid, a different type of football, and he will bring a lot of good quality and mentality."
Partey is in line to make his full Arsenal debut when Mikel Arteta's men travel to Rapid Vienna for their Uefa Europa League opener on Thursday.
Meanwhile, former Arsenal scout Francis Cagigao described the Black Stars midfielder as a long-time target and 'the final piece of the jigsaw' which makes the North London outfit title challengers.
"He is a player that we pursued for a long time and strongly recommended over the last few years," Cagigao said.
“I first watched him about six years ago playing for Almeria on loan from Atletico Madrid and he was more box-to-box, attacking even. I think we will see him with the shackles off because he did very much play in a constricted midfield unit [at Atletico].
“He could be the final piece of the jigsaw that makes Arsenal challenge for the title.”