London - Paris Saint-Germain coach Laurent Blanc on Tuesday told his players to be wary of underhand tactics from Chelsea striker Diego Costa ahead of Wednesday's Champions League last 16 return leg.
Having claimed a 1-1 draw in the first leg in Paris, Jose Mourinho's Chelsea hold the upper hand in the tie as they attempt to reach the quarter-finals for the fourth time in five seasons.
PSG must score to stand any chance of progressing, but Blanc is also concerned about the bruising Costa, who has attracted as much attention for his goals -- 17 since joining Chelsea from Atletico Madrid last year -- as for his rough-house tactics.
"We know him very well. He's changed country, club and mentality, but I think the English championship suits him well," Blanc told a press conference at Stamford Bridge.
"He's a boy who likes contact, who likes a duel, who's a bit provocative. We'll have to hold our nerve and not get involved in his games.
"He needs that to bring out the best in him. I saw him in the League Cup final against Tottenham (which Chelsea won 2-0), and he was looking to do that right from the start.
"So tomorrow night (Wednesday) the centre-backs or players around him will have to make sure they're effective in stopping him.
"He's a physical player, technical too, but he'll try to provoke a reaction and we must not get caught up in his games, particularly as we're away from home."
Blanc also suggested that Chelsea might be tempted to indulge in gamesmanship in order to protect their advantage, but said he had no concerns about Dutch referee Bjorn Kuipers's ability to control the game.
"On the refereeing, I'm pretty calm," Blanc said. "The referee is experienced in the Champions League.
"I hope he puts in a good performance and the teams go out there and try to play football.
"Chelsea will try and employ certain tactics to keep things going their way -- we do that as well -- but it's about having experience in these big matches."
PSG were knocked out by Chelsea in last season's quarter-finals after a 3-3 aggregate draw, with Demba Ba's 87th-minute strike in the second leg earning the London club a 2-0 win that took them through on away goals.
But whereas Zlatan Ibrahimovic was missing for PSG due to a hamstring injury, he is fit to face Chelsea on Wednesday and Blanc backed the talismanic Swedish striker to make his presence felt.
"The French press might always be asking questions about Zlatan's influence in Champions League knockout games, but I think that whether it's (John) Terry or (Gary) Cahill or (Kurt) Zouma, whoever plays at centre-back for Chelsea, I don't think they'll be happy to play against him," Blanc said.
"We know that he can score at any moment, against any team, and in any stadium. And that will be important for us."
Blanc also confirmed that PSG's players will wear black armbands as a mark of respect for the 10 people -- including three prominent French sports personalities -- who died in a helicopter crash in Argentina.