"He was limping quite badly after the match as you know," Arteta said on the club's official website.
"We had to get him off the field, which is never a good sign as well. He hasn’t been able to participate in the session."
When asked if he could miss the match at the Vitality Stadium this weekend, Arteta responded: "It’s a possibility, yes."
Saka has played in 86 consecutive Premier League matches, a club record, and has started the season in fine form, having scored three goals and provided two assists so far.
Potential impact in FPL
The news is also a potential blow to his Fantasy Premier League managers.
Saka (£8.7m) is the joint-highest scoring midfielder in the game so far, with 44 points, and is owned by over 6.5m managers, or two-thirds of Fantasy managers, making him the second-highest-owned player in the game after Erling Haaland (£14.1m).
"Declan hasn’t trained yet. Obviously he could not carry on in the game, he wasn’t comfortable at all.
"Hopefully it’s not something big. We are confident. He’s still uncomfortable, obviously he had to leave the pitch and that’s never a good sign for a player like him, but hopefully he will progress in the next few days. It’s a tough one.
"Leandro won’t be available for tomorrow. Let’s see day by day how he improves and whether he’s got a chance for the weekend or not. He did some activity and that’s where he felt it.
"He wasn’t comfortable to carry on the session the day before the game and he hasn’t trained yet, so not available for tomorrow.
"Tomorrow is too short for Gabriel. Let’s see if we still have this for the weekend, but those players won’t be available tomorrow.
"Thomas is still not available either. It’s a long list, as you said. It’s the same with Jurrien, you know that one, and it’s the situation that we have at the moment. We have to adapt. The squad that we have at the moment is really short and we need players back, that’s for sure."
Arsenal are in EFL Cup action on Wednesday against Brentford before taking on Bournemouth.