The England midfielder spent four months out of action at the start of the season with a thigh strain and now, after a run of seven appearances, has been ruled of this weekend’s clash with the Baggies by a minor muscle tear.
“Adam Lallana has a little issue which I think, pretty sure, keeps him out for the next game,” Liverpool manager Jurgen Klopp told reporters on Friday.
“It is not a big one but it is how it is when you have a long injury.”
The German added: “Adam had a long injury and then there comes a few things because he needs time again to adapt to the intensity of a Premier League game.
“We tried to be careful with that but obviously so far it didn’t work very well.”
Lallana has managed just one start since returning at the end of November, with James Milner also likely to be absent from Liverpool’s midfield against West Brom because of a leg problem.
But, in better news for the Reds, Liverpool captain Jordan Henderson may return after a month out with a hamstring injury.