Manchester United manager Ole Gunnar Solskjaer has warned his players to expect an aggressive Manchester City side to be "snapping at their heels" and fouling them in Wednesday's derby.
The two sides will meet in a high-stakes clash at Old Trafford, with City locked in a tight Premier League title race with Liverpool and United scrapping to get into the top four.
City have previously been accused of 'tactical fouling' to prevent counter-attacks when they are pressing high up the pitch, and Solskjaer expects to see that on Wednesday.
"We have got to be ready for the press and the quality they have got on the ball," he said.
"When we win it we have got to be ready for their aggression because they will snap at your ankles and heels and kick you.
"They will not allow us easy counter-attacking. There will be fouls, no doubt about it."