Samuel Umtiti was, along with Riqui Puig, left out of the Barcelona squad for the Champions League game against PSV Eindhoven on Wednesday.
The French player, who came back from injury against Atletico Madrid at the weekend, will have to watch the game from the stands.
Among some people at the club there's concern about Umtiti's fitness because he already had problems with his knee.
Even when he came back at Atletico he was a doubt until the last minute. The decision to leave him out in Holland is not a very good sign as it means he's still struggling.
Barça said: "During training on Tuesday, he suffered from pain in his left knee and is out of the [PSV] game."
With Umtiti missing, his place, once again, has been taken by summer signing Clement Lenglet.