Sergio Aguero is felling better every day after returning to training but Pep Guardiola is unsure when the Manchester City striker will be available for squad selection.
City's all-time record goalscorer has endured a frustrating campaign and has not featured since coming on as a late substitute in the 3-1 win over Chelsea on January 3.
That is one of only nine appearances made all season by Aguero, who struggled with knee and hamstring issues before being struck down with coronavirus last month.
He returned to training on Monday but Guardiola cannot say for certain when the Argentina international will feature again.
"Yesterday he trained with the group for 10-15 minutes and later did some part alone," Guardiola said at a news conference ahead of Wednesday's FA Cup tie with Swansea City.
"Day by day he is feeling better. Is he ready? Not yet."
City make the trip to Wales on a 14-game winning run in all competitions, including a 4-1 victory over Liverpool on Sunday to tighten their grip on top spot in the Premier League.
That equals the all-time winning run by an English top-flight side but Guardiola has warned his players they cannot afford to take last-16 opponents Swansea for granted.
"I can't explain it. I just think about the next game and try to prepare for it as well as possible - there are no more secrets than that," the Catalan coach said.
"We are so calm when we lose and the same now we are winning. The reason why is thinking the next game and now it's Swansea."
City's winning run has come despite the absence of Aguero, with Guardiola often preferring to go without a recognised striker up top - as was the case against Liverpool.
"We play with a centre forward many games," Guardiola said. "When we don't play with a typical centre-forward people can move a bit more but we have to arrive in the box.
"We saw the game against Liverpool - four or five players were inside the box. Every game is different.
"We are looking forward, even Gabriel [Jesus] is dropping, improving in his position not playing like a player you can link and the striker just being there.
"I'm not a big fan of this. I prefer to move behind this position and we have some players who can do it."
Wednesday's clash at the Liberty Stadium will be the first between Man City and Swansea since a dramatic FA Cup quarter-final in 2018-19, which the Citizens edged 3-2.
Guardiola's men have won 12 of their last 14 meetings with Swansea in all competitions, including each of the last six in a row.
However, the Welsh side have been in good form of their own of late, winning eight and drawing two of their last 10 matches, and are seeking to reach the last eight for a third time in four seasons.
Guardiola saw his side survive a scare against fourth-tier Cheltenham Town in the last round and is expecting another tough test against Championship promotion contenders Swansea.
"Swansea have a tradition of good managers: Michael Laudrup, Roberto Martinez, [Graham] Potter - now I realise how good he is as we suffered a lot when we played Brighton," Guardiola said.
"It was a difficult game the last time we played Swansea. I don't expect a different game to when we suffered there two seasons ago to go through.
"I know they are consistent, score, good defensively, don't concede chances, so solid in their formation, physically strong, they have the quality to play upfront and in the middle.
"It will be an incredibly difficult test. We have to do a good performance. We suffered against Cheltenham, 1-0 down with 80 minutes. I don't expect a different game tomorrow."
Man City have won 18 of their 21 FA Cup ties under Guardiola and have scored more goals (65) in the competition since the Catalan arrived in 2016-17 than any other side.