Paris Saint-Germain coach Laurent Blanc has revealed Marco Verratti could miss next week's Champions League meeting with Chelsea, while he also has concerns over Blaise Matuidi and former Blues defender David Luiz.
PSG beat rivals Marseille for the ninth time in a row on Sunday and their 2-1 away win stretched their record unbeaten run in Ligue 1 to 34 matches.
However, the victory came at a price with both Matuidi and Luiz said to be feeling the effects.
PSG midfielder Javier Pastore, meanwhile, aggravated a calf problem at training on Saturday, while Verratti sat out the Marseille game to rest a groin injury.
Having last week revealed that the Italy international needed a rest, Blanc said on Sunday that Verratti would be given as much time as possible to prove his fitness ahead of the Champions League round-of-16 first leg against Chelsea on Feb. 16.
"I'm not sure if he'll play against Chelsea," Blanc told a postmatch news conference. "We're optimistic. He's 100 percent indispensable to PSG."
Matuidi asked to be taken off for precautionary reasons with eight minutes left on Sunday, but Blanc said he believed the club had "intervened in time."
The midfielder remains hopeful that he will be ready to feature in PSG's next matches against Lyon in the Coupe de France on Wednesday, Lille in Ligue 1 on Saturday and the Chelsea clash next week.
"I felt a pain in my adductor [muscle]," Matuidi told reporters. "We'll see how things develop in the next few days. I hope it's going to be OK."
PSG are 24 points clear of Monaco at the top of Ligue 1 but Matuidi said the number of matches they have been playing is still taking its toll.
"We have a big lead in the league," he said. "It's allowed us to rotate the team from time to time. But despite that, we've still got a few niggles. So we have to be careful and remain concentrated like we have been."
Luiz refused to be substituted against Marseille despite looking in discomfort when forced to leave the field with 12 minutes left to play.
Blanc said the Brazil international had some pain "behind his thigh" but that the injury was not serious because he had returned to finish the game.
"It's tiredness -- normal, logical," Blanc said. "The problem is you need a bit of time to recover and we're playing again in three days. We'll make do."