Bukayo Saka has joined Arsenal's growing injury list after Mikel Arteta revealed the England forward is struggling with a foot problem.
Arteta limped off in the closing stages of Sunday's 2-2 draw against north London rivals Tottenham.
The 22-year-old will definitely miss Arsenal's League Cup third round tie at Brentford on Wednesday and could also be sidelined for Saturday's Premier League game against Bournemouth.
If Saka is unable to feature this weekend, it will end his club-record run of 86 consecutive Premier League appearances.
"He was limping quite badly after the match. We had to get him off the field, which is never a good sign. He hasn't been able to participate in the session," Arteta told reporters on Tuesday.
Asked if he could miss the Bournemouth game, Arteta added: "It's a possibility, yes."
Saka is the latest Arsenal star to catch the injury bug after England midfielder Declan Rice was replaced at halftime against Tottenham with a back issue.
Brazil forward Gabriel Martinelli and Belgian winger Leandro Trossard missed the derby through injury, with Jurrien Timber and Thomas Partey also sidelined by long-term fitness problems.
Losing Saka, who has four goals and four assists from the first eight games this season, for a sustained period of time would be an especially painful blow for Arteta.
Arteta once again highlighted the amount of football being played as a potential explanation for so many injuries.
"It's true that they play with the national teams and they're coming from a season where they had a World Cup and some players played 60-odd games," he said.
"We've been unlucky. Jurrien, for example, was due to other reasons, while Bukayo was because someone stepped on him.
"There are some traumatic injuries, others are more muscular. We try to find the ways to avoid them but they're a part of football.
"It's true that we have a lot of internationals in the last few windows and they have quite a lot of exposure to minutes but at the moment we have a squad that is not 24 players. To change 11 or 12 players tomorrow is just not a possibility we have."