London - Chelsea could be without central defensive pair Gary Cahill and John Terry for Saturday's FA Cup clash at Manchester City.
The Blues had hoped Terry would be fit for Tuesday's Premier League game at West Brom where Victor Anichebe's late equaliser for the Baggies cancelled out Branislav Ivanovic's opener in a 1-1 draw that left Chelsea just two points in front at the top of the table and at risk of being overhauled by both Arsenal and City, each in action on Wednesday.
But instead the Chelsea skipper remained sidelined with the muscle injury that kept him out of Saturday's 3-0 win over Newcastle.
Meanwhile Cahill became an injury worry for Chelsea when he limped off shortly before Anichebe's 87th-minute goal at The Hawthorns with a damaged calf.
"Once I got the knock, I was struggling from then on," Cahill told Chelsea's website.
"It happened when a West Brom player went for a header and I was on the floor, and he landed just inside my knee/calf.
"It's sore and we'll see what it's like later."
Chelsea playmaker Eden Hazard, well-shackled by West Brom following his hat-trick against Newcastle, said Tuesday's trip to the West Midlands had been an awkward one for Jose Mourinho's title challengers.
"It was a puzzling game," Hazard said. "At 1-0 I thought we were managing the match well, but we couldn't get the second goal which would have given us protection, and then the game became difficult.
"I tried to play, we tried to play, but it was a very difficult game.
"It was very complicated whenever I had the ball because there were two or three opponents there.
"They had a plan to defend, as was the case when we played West Ham.
"It was a similar situation except at the end West Brom pushed a lot, their crowd got behind them and it became complicated.
"But it's still a point even if many people are disappointed. I think this is a point that will count.
"You cannot win every game and it was important we didn't lose. We'll improve in the future and we will try to win the next game."