Thiago Alcantara will not be rushed back into action despite returning to Liverpool first-team training, according to boss Jurgen Klopp.
The Spain international has missed more than two months of action since sustaining a knee injury in the Merseyside derby against Everton on October 17.
Having also had a spell out after testing positive for coronavirus, the 29-year-old has only played twice for Liverpool since arriving from Bayern Munich in a deal that could reach £25million.
He started training with the rest of the squad on Wednesday but Klopp confirmed Sunday's Premier League game against West Brom will come too soon for him, although the Reds boss had better news on the possible returns of Xherdan Shaqiri and James Milner.
"Thiago made his first steps back towards team training," he told a media conference. "He's not involved in the full session but has made good steps. Unfortunately, after a long time out we cannot and will not rush it.
"The other guys are closer. Shaqiri trained really well. Milly trained a full session yesterday and today a little bid adapted.
"It's a strange situation for us because we still have two more days before we need to make a decision but I don't know. Thiago will not be involved, he has to be in full training first. He's not too far away, I hope."
After an intense period of six games in 19 days, Liverpool are enjoying an eight-day gap between the 7-0 win over Crystal Palace on Saturday and the visit of West Brom this weekend.
Klopp says it has allowed his players to undertake more varied training, which he believes will stand them in good stead ahead of the busy Christmas and New Year period.
"This week was a really important week," he added. "Today was the first 'minus three [days]' session since we started again, so full 11 on 11, tactical stuff, everything in, pressing, counter-pressing, all the stuff. We haven't had that.
"So, this is the most similar session you can have to playing a game. The boys are connected, the boys are important and we will use them.
"Against Tottenham we didn't make a substitution because they were all without rhythm and the game was really intense. They are now all a step further."
Liverpool will be quietly confident of extending their unbeaten run in the top flight to 11 games against a side who have won just once in 14 outings so far this season.
Baggies boss Sam Allardyce, however, is unbeaten in his last three away Premier League games against the champions and was the last opposition manager to win at Anfield in the competition, doing so with Palace in April 2017.
With that in mind, Klopp is taking nothing for granted and expects a tough game against the league's 19th-placed side.
"Of course, it's a tricky one," he said. "We analysed it this morning. It's a mix of when Sam was at Everton and then his first game at West Brom against Aston Villa.
"I expect a tough opponent, well organised, don't make a big fuss of possession and it will be a proper fight. Sam is a proven specialist for organising teams for these kinds of fights. A tough game."