Pep Guardiola believes Manchester City will be without Raheem Sterling for "weeks" and cannot be sure whether the forward will be fit for their upcoming Champions League trip to face Real Madrid.
England international Sterling suffered a hamstring injury in Sunday's Premier League defeat at Tottenham and will miss this weekend's home match against West Ham .
City have not specified the severity of the damage Sterling has sustained, and Guardiola did not offer any guarantee that the 25-year-old will be ready to return to action before the end of February.
After the West Ham game, City take in their winter break, with their next match coming against Leicester City on February 22, followed four days later by a clash with 13-time European champions Madrid at Santiago Bernabeu.
To lose a potential match-winner such as Sterling would be a major blow to City's hopes of beating the La Liga leaders.
And when asked about Sterling's situation, Guardiola told a news conference: "Of course it takes weeks, but we will see before Leicester, Madrid and the rest of the games. I don't know right now.
"It is a problem. [Injuries are] always a problem, but it is what it is."
Sterling's absence leaves Guardiola with few options in terms of wide attackers, with Leroy Sane still recovering from the cruciate knee ligament injury that has ruled him out of action since the Community Shield in August.
The Germany international, who is a transfer target for Bayern Munich, has returned to full training, but Guardiola insists he will not be rushed back into action ahead of schedule.
"He’s started to train with us, he is still not there," he said of the former Schalke star. "When you have an injury, especially this one for six months, you need to recover, tempo, rhythm, confidence in your knee, and don’t think about the injury.
"He needs time, it’s not a case of him training and he will then immediately be there, it’s not like an ankle or a muscular injury. This injury it needs time.
"He needs weeks. What’s important is the surgery was perfect and he’s recovering incredibly well, he’ll come back stronger than before but now he needs a little bit of time.”