Chelsea manager Antonio Conte admits he is worried over Alvaro Morata's back injury and does not know when the Spain international will be available for selection again.
Morata, who has scored 12 goals so far in what is his first season at the club following a summer move from Real Madrid, has missed four games with the problem; the Premier League defeats to Bournemouth and Watford, the Carabao Cup loss to Arsenal and an FA Cup victory over Newcastle United.
The arrival of Olivier Giroud from Arsenal on transfer deadline day has provided Conte with an able deputy in the Spaniard's absence, but the Chelsea manager admits the club's medical staff are still to get to the root of the problem.
After confirming Morata will not be back for the visit of West Bromwich Albion on Monday [12 February], Conte told a press conference, broadcast through Chelsea TV: "Giroud has trained and will be in contention. We are talking about a lot of bad results, but sometimes we forget we are facing a serious situation.
"Players like Morata are very important for us and have been missing for a long time. I don't know how long he will be out. We are struggling to find a solution to solve the pain in his back. If you ask me whether he needs a day, a month or the rest of the season, I don't know. For this season, I am a bit worried. You very well the importance of the player."
Conte has slightly more positive news on Andreas Christensen. The 21-year-old centre-half limped off before the half hour mark against Bournemouth on 31 January, with the Blues going onto concede three times in his absence in that contest. That hamstring problem also ruled him out of the 4-1 defeat to Watford last Monday.
While the Dane missed training on Friday, Conte remains hopeful he will be able to return to the starting XI for the visit of Alan Pardew's side.
"Honestly I hope to count on him for West Brom. He is an important player for us," Conte said.
Pedro was another injury victim in that defeat at Vicarage Road and was helped off the pitch by the Chelsea medical stuff after appearing to hurt his ankle. Conte however said on Friday the former Barcelona star is "okay" and will be in contention for Monday.