Enzo Fernandez appeared to suffer a knock during the second half of Chelsea's defeat to Manchester United. The 25-year-old midfielder requested to come off in the final minutes of the game after falling awkwardly inside the opposition box.
With the Blues chasing an equaliser, Fernandez was swiftly replaced by Lavia. It was the second time that Liam Rosenior was forced to make a substitution at Stamford Bridge on Saturday night; Estevao Willian pulled up with a hamstring problem in the opening quarter of an hour.
As it stands, the severity of the Argentina international's potential injury remains unclear. The Chelsea boss will be expected to provide an update on the two players in his post-match press conference.
Fernandez coudln't transform the Blues' fortunes upon his return to the starting lineup. The Argentine, who had cast doubt over his future at Stamford Bridge during the international break, served the final game of his in-house two-match suspension last weekend, when Manchester City ran riot.
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Unsurprisingly, Fernandez wasn't named as captain on Saturday evening, with Moises Caicedo donning the armband. Speaking to reporters at Cobham on Thursday afternoon, Rosenior commented on the saga.
On whether the situation affected the squad, the Chelsea boss said: "Not that I'm aware of, no. No, Enzo's come back to the group this week. The group's been fantastic in terms of his training, Enzo has as well, and his application to training, and our group's application to training, so no."
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On what has been a difficult period for the Blues, Rosenior said: "I think obviously we're not in a good place in terms of the results. It's a brilliant challenge in terms of myself, in terms of my energy, what I give the team, and more about what we do together.
"We've had a lot of really strong conversations as a group. We've had some very, very good training sessions. I think in this moment, you find out about yourself, you find out about your group, and you actually just have to stay focused on the process, which is here, the day in, day out."
On keeping the group together during a rocky spell, Rosenior said: "The noise is not anything that you can control. What you can control are your group in terms of our spirit, which I don't think has ever been in question.
"I don't think there's been a lack of effort, especially the game against Manchester City. We're playing against probably the most in-form team definitely in this country right now, and for 50 minutes, 55 minutes, we're well in the game, if not the better team.
"Then a moment happens, then you lose confidence. The team are together, we're united, we know we all want to be successful together. That's not a question for the moment."
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