Tottenham midfielder Dele Alli was compared to a "wild horse" by manager Mauricio Pochettino.
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.
"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?"
"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."
