Chelsea players including new striker Pierre-Emerick Aubameyang trained in Croatia ahead of Tuesday's Champions League Group E opener against Dinamo Zagreb.
Aubameyang joined the Blues on transfer deadline day from Barcelona but was thought to be weeks away from first-team duty as he recovers from an injured jaw following an attack by armed men at his family home in Spain.
But the Gabon international, 33, could be in line to make his debut for the London side in Zagreb wearing a protective mask for his injured jaw but Chelsea manager Thomas Tuchel on Monday implored the media not to give him ideas of being a 'superhero'.
Tuchel joked in his pre-match press conference: "Don't put any ideas into Auba's head please, any further ideas.
"I'm pretty sure he has his own ones. When he scores he can celebrate. First of all, he needs to score.
"He's very ambitious, very focused. He's hungry to play for us and prove a point. That's why he's here, that's what we felt from the first moment. He's happily invited to prove a point tomorrow."
Although his current mask is for medical purposes, in the past Aubameyang has celebrated goals by donning masks of comic book heroes — including Batman, Spider-Man and Black Panther — saying he puts them on to make his kids happy.
Tuchel said a call on Aubameyang playing would be taken depending on how he trains again, but would not play the full match.
"Is he ready to start? Of course. He cannot play 90 minutes," Tuchel added.
"It's on us to take a decision on how we manage the minutes. He needs minutes to get his full fitness and rhythm. It's on us to find a solution if he comes from the bench or if he starts."