Sergio Aguero remains unavailable for Manchester City's Premier League game against Aston Villa on Wednesday.
City's record goalscorer has missed City's last three games after being told to isolate as a close contact of someone who has tested positive for Covid-19.
Speaking at a press conference on Tuesday, manager Pep Guardiola said: "He is not ready for tomorrow, he is still isolated."
Guardiola admits City have missed the presence of Aguero, who has also had knee and hamstring problems this season, but feels they have coped relatively well.
He said: "We need him, we miss him, his numbers speak for themselves. He's the best striker in our history. He can create and win games for himself.
"We could have complained but we did the opposite. We want him back but we have to move forward, find alternatives, use the quality we have."
Asked if City might look to strengthen their squad in the January transfer window, Guardiola said: "No."
Guardiola gave a slightly more detailed answer when asked a similar question in an interview with beIN Sports: "We will not sign any deal during the winter transfer market. We did not discuss this, but we will end the season with the players that we have now."
Aside from an FA Cup tie in which they fielded a youth side, Villa have not played a match since New Year's Day due to Covid-19 issues.
It is unclear how strong a side Villa will be able to field but Guardiola is working on the assumption they will be at full strength.
He said: "We expect the best. I don't know the situation, I wish they are healthy and all recover well and come back healthy. This is the most important thing and I expect the best."
Defender Aymeric Laporte remains on the sidelines through injury but the Frenchman is close to returning.
Guardiola said: "He is in the last step, not (ready) for tomorrow but he started training with us yesterday."
