Mikel Arteta has said Bukayo Saka will only be sidelined for a "couple of weeks" -- but admitted it is a "big concern" that the England star has suffered two hamstring injuries in eight months.
Saka was withdrawn in the second half of Arsenal's win against Leeds at the Emirates last weekend, and he will be absent for his side's trip to Liverpool on Sunday.
However, the injury is not as bad as first feared and it is anticipated that the 23-year-old could be in a position to return to action next month.
Saka missed 3 ½ months of last season following surgery on his right hamstring in December. He returned in April and played 13 times before picking up another hamstring issue, albeit in his left leg, in just his second appearance of the new campaign.
"He [Saka] does not need surgery," Arteta said. "It's not as bad as the previous one. He felt something, so he will be out for a couple of weeks.
"But it is obviously a concern, a big one, especially when we talk about a sprinter and a player that gets into that zone very often in a football match, who needs that burst, that change of rhythm of pace to be as threatening as possible.
"But we will learn again as to why it happened and make him stronger. Unfortunately injuries are part of a career. He hasn't had that many to be fair with the amount of games that he has played at his age but it is something that we want to eradicate."
Arteta could be without as many as seven players for their blockbuster clash against the Premier League champions. Saka, Gabriel Jesus and Kai Havertz are all out, while Martin Ødegaard, Christian Nørgaard, Leandro Trossard and Ben White are doubts.
Havertz underwent what the club described as a minor surgical procedure on his knee this week. However, captain Odegaard could yet feature at Anfield despite falling awkwardly on his shoulder in the win over Leeds.
- Source: Arsenal seek Hincapie loan from Bayer
- UCL draw analysis: Good games for Arsenal, bad for PSG
- Biggest ties: Madrid face Liverpool, City in daunting UCL draw
"It is very unfortunate, and very sad for him," Arteta said of Havertz, who missed three months of last season with a hamstring injury.
"He did tremendously well to recover from the previous one. He's never had an injury before. And suddenly this happens.
"Obviously, we lose another big player for many, many weeks. But it was the right thing to do. The doctors advised and he was very convinced at the end that it was the quickest and the best way to resolve that issue.
"For Martin, he hasn't trained yet, and if he does, it will be tomorrow. He's doing everything he can, and we're doing everything that we can to make him available. There's an injury there, but hopefully if everything goes well, he can cope with it."
Arsenal finished runners-up to the Reds last season, 10 points behind Arne Slot's side.
And when asked if Liverpool are the favourites to retain their crown, Arteta concluded: "The favourite is always the one that won the previous year.
"Somebody has to come and take that crown away from them so that is what we will try to do. The aim is to be better than them."