Tottenham manager Mauricio Pochettino says midfielder Dele Alli is like a "wild horse" that needs to be tamed.
The England international, 20, was banned for three games last season for punching West Brom's Claudio Yacob, while he also kicked out at Fiorentina defender Nenad Tomovic.
Pochettino said the aggressive side of his game was something Alli needed to maintain to give him an edge.
"He is a big talent but he was a bit wild," the Argentinian said. "Now he is more domesticated. You can't lose that side - it might make him a special player."
Pochettino added: "It is like when you have a wild horse and you need to put it in a box and domesticate it, no?"
Alli has scored three goals in eight Premier League games this season, helping Tottenham sit third in the table. Pochettino is pleased with what the midfielder has produced so far this campaign.
"There is nothing to say about Dele. I am more than happy with him, the effort in every game," he said. "He plays a lot, he brings to the team many positive things and if every chance that he has he will score, maybe we are talking about a Marco van Basten or a Gabriel Batistuta, a striker. Not a midfielder offensive, a number 10.
"I think he works hard, he presses, he scores, he creates chances. I think it is unbelievable all the effort he makes in every game."
The next outing for Tottenham is a trip to Bournemouth in the league on Saturday.