Mauricio Pochettino is hoping Reece James' latest setback is not a major one after the Chelsea captain suffered another hamstring injury in their 2-0 defeat to Everton.
Pochettino also suggested the Blues need to make even more signings in the January transfer window, despite over £435m being spent over the summer. Chelsea are languishing 12th in the Premier League, having won just one of their last five games, and Pochettino believes they need more firepower.
"After the first half of the season, we need to check," he said after the Everton defeat. "That is the reality. If we are not receiving enough, maybe we need to do some movement. That is the thing to analyse with the sporting directors, to see if we can change this dynamic and improve in the second half of the season.
"We need to be more aggressive. Then it's a massive assessment and when the transfer window opens, we will see what we can do. I don't say if I am going to ask for more or less players. It's to see if the perception matches the reality. We are missing something."
And when asked about James' injury, Pochettino revealed: "Reece felt something in his hamstring. For sure he's injured, but we don't know how serious it is. Of course for us he is an important player, one of the best full-backs in the world.
Premier League odds and betting tips"It is really disappointing because after 15 or 20 minutes we were playing well and I think this type of circumstance makes us change, because of course Malo Gusto is recovering from his injury. We hadn't given away many chances and then you need to move things to make some changes.
"Even when Reece went off the team was pushing and playing well. But we are disappointed because when you believe you can build something and a player like him who should be really important for us can't help the team. We go back and assess again in the next few days what is going on with his hamstring."
Goalkeeper Robert Sanchez and left-back Marc Cucurella were also forced off during the game adding to Pochettino's woes. "Robert Sanchez suffered a problem at Manchester United, it was an issue with his knee," he explained.
"He felt something during the second half, that is why he asked for the change. We must hope it is not a big issue. That is the same for Marc Cucurella, who twisted his ankle. We hope that these issues are not big.
"These are the circumstances we have been dealing with since the start and it is too much for a young team that needs to have all the elements together if we want to build something solid."