Mohamed Salah has spent time in a hyperbaric oxygen chamber following his knock in Liverpool's Champions League victory over Manchester City.
The Egyptian winger pictured himself inside the recovery apparatus on his Instagram page on Thursday, after being forced off in the second half of the 3-0 quarter-final first-leg win at Anfield.
Hyperbaric oxygen is widely used in sports science to help with recovery. It is supposed to help with the reduction of swelling, facilitate healing and reduce fatigue.
Liverpool planned to assess Salah after he was replaced on 52 minutes by Georginio Wijnaldum and went straight down the tunnel alongside a Liverpool physio while appearing to indicate an issue in his groin.
Manager Jurgen Klopp indicated at full-time that Salah had told him he was "fine", but they must determine a clinical diagnosis before making him available for Saturday's Merseyside derby against Everton, live on Sky Sports.
"About Mo, I don't know. He came to the sidelines and said he felt, sometimes, something," Klopp said. "That was enough for me to not even ask the doctor how he is, but to take him off the pitch.
"After the game I asked him and he said 'no, it's fine, I will be good'. But now we have to wait for the real diagnosis and not Mo's self-diagnosis."
Salah had pounced inside the box on 12 minutes to finish off an excellent counter-attack and give his side the lead, before Alex Oxlade-Chamberlain and Sadio Mane also struck to make it 3-0 before half-time.