Liverpool star Diogo Jota has returned to Anfield after struggling to overcome a worrying muscle injury on international duty.
The Portuguese forward, 24, is now a serious doubt for the Reds' trip to Watford this coming weekend.
Jota was not part of the national team's squad for their 3-0 victory against Qatar on Saturday and has been ruled out of Tuesday evening's World Cup qualifier against Luxembourg.
The player was working on a conditioning programme with physios but has now been considered "unavailable" by Portugal's medical team.
It's unclear when Jota will return to action and Liverpool boss Jurgen Klopp is also sweating over the fitness of Trent Alexander-Arnold, Thiago Alcantara and Curtis Jones.
Alexander-Arnold and Thiago both missed the Reds' recent game against Manchester City with muscular ailments and Jones has groin problem, although he did feature in England U21's 1-0 victory against Andorra on Monday.
Klopp will also be concerned about Alisson Becker and Fabinho, who are set to play for Brazil in their upcoming World Cup qualifier against Uruguay.
The game is scheduled to start at 1:30am on Friday morning (UK time) - just 35 hours before the Reds kick-off against Watford.
Liverpool's Brazilian stars are not expected to play on Saturday and could travel directly to Spain for the team's Champions League clash with Atletico Madrid on October 19.
Jota missed more than two months of last season with a knee injury and Klopp will be hoping he can return to fitness sooner rather than later.
The former Wolves star has impressed at Anfield when fit, scoring 16 goals in 39 appearances since joining the club in September 2020.
Discussing Jota's fitness on Monday, Portugal manager Fernando Santos said: "He trained a while ago, increased the intensity today with [physio] Joao Brito, but he didn’t train with us.
"The probability [that Jota will play] will be little. I’ll talk to him and see how he feels. If we see that he is in any condition to be on the bench and then he can come in, that’s fine.
"If we don’t, we won’t take the risk with a player who hasn’t been able to train with us for a long time. I’ll make the decision shortly, and if he can’t play, he’ll head back to Liverpool."
