David Moyes says Nigerian forward Victor Anichebe is one of the key players Sunderland are banking on to avoid relegation.
Sunderland are currently 19th in the league table.
Anichebe who has scored three Premier League goals, sustained a hamstring injury in Sunderland's 4-1 away defeat to Burnley on new year's eve.
Aside Anichebe, Moyes also made mentioned of promising young keeper Jordan Pickford who is out injured.
"We've lost one or two people who were key in our winning run – Victor and Jordan – and they are both really important players," Moyes said during his Friday's pre-match press conference.
Moyes revealed that Anichebe, Steven Pieneer and Jack Rodwell's availability is still an uncertainty for the game against West Brom.
"I'm not sure if anyone will be back. There was only a chance with Steve Pienaar and Victor Anichebe.
"Jack Rodwell should be okay. He had a slight problem with his knee but a scan revealed there was nothing there.
"Jordan Pickford sees a specialist next Tuesday and he'll be the one to tell us if he's in the clear to come back."
Speaking ahead of Saturday's game, Moyes praised the West Brom for their performances so far while stating he is relishing going against old foe Tony Pulis.
"West Brom have done a good job and they're starting to chase the teams above them.
"I've been coming up against Tony for what feels like 100 years! He was at Gillingham when I was at Preston, so we've been around."
And on the transfer front involving players coming in and going out of Sunderland, Moyes said: "We've been linked with four or five players this week and I can tell you that none of them are the ones we're in for."
"I'm not aware of any interest from Crystal Palace in Lamine Kone at present."