Liverpool forward Mohamed Salah was forced off the pitch against Newcastle United on Saturday with a suspected head injury.
The Egyptian forward, who scored Liverpool's second goal of the match, had to be taken off on a stretcher following a collision with Newcastle's Martin Dúbravka.
There hasn't been any official confirmation about Salah's current condition, but it has been speculated that the suspected concussion could force the 26-year-old to miss the rest of the season as a result of his injury.
That means that Salah will miss Liverpool's upcoming Champions League semi-final second leg against Barcelona, where they're looking to overturn a three-goal deficit to progress to their second final in as many years.
Goals from Luis Suárez and two from Lionel Messi proved to be the difference at the Camp Nou, although Barcelona proved last season that a comfortable win at home in the first leg isn't always enough to progress.
Salah's teammate Roberto Firmino could also be out of action at Anfield in midweek, as Jürgen Klopp has confirmed that the Brazil international is still struggling to return to full fitness.
"Bobby didn't start at Barcelona as well," Klopp said, quoted by Sky Sports. "He's had problems, he still has problems. He's not even in the squad, he's just not available. That's how it is.
"So we have to accept it and that's why it's easy to leave him out because the medical department said no chance."