Paris Saint-Germain manager Laurent Blanc has called on his players to "stay calm" when facing Chelsea striker Diego Costa on Wednesday evening.
Costa was involved in a number of tussles with PSG players during the first leg of the Champions League last-16 tie in Paris last month, and Blanc believes that the former Atletico Madrid forward needs aggression in his game to have a greater impact in matches.
The 49-year-old told reporters: "He likes contact, and provokes opposition players. That's part of his game. He thrives off that. He really needs that to bring out the best in his performances.
"The most important thing is to not get caught up in the way he plays. He will try to provoke a reaction. We need to stay calm, not get caught up in his game. We need to be as effective as possible in stopping him."
The two teams head into tomorrow's second leg at Stamford Bridge with the score currently at 1-1 on aggregate.