Leeds United manager Jesse Marsch wants to see Jack Harrison develop a nasty streak.

The English winger played against Marsch's New York Red Bulls when he was playing in the MLS for New York City FC.

Harrison has been a positive light for Leeds this season, but Marsch wants him to be more aggressive.

"When we've had players from the US or MLS that have come over, I've tried to see what their adaptation has been like and how they've grown," Marsch told a press conference ahead of Thursday's game against Aston Villa. "I could see that Jack had taken a lot of new responsibility here.

"He was always the type of player who was very respectful and would shake my hand and say 'good game'. I'd heard he was a really good young man and it's clear to see. What I've tried to say to him is it's OK to be a good young man and to be a son of a b*tch on the pitch.

"He has such quality and my goal is to push him and his personality and his level of play on the field so that he can use all his strong qualities as a human being to benefit him, to continue to grow as a player, and become as dangerous, as effective as I believe he can be."