Martin Odegaard was left with his knee in a brace and Declan Rice was forced off with a back problem as Arsenal's injury issues intensified during their 2-0 win over West Ham.
The Gunners went top of the Premier League thanks to Rice's opener and a Bukayo Saka penalty at the Emirates Stadium but the win came at a cost as Odegaard and Rice had to be withdrawn.
Odegaard, who had only recently returned from a shoulder problem, lasted just half an hour, becoming the first player in Premier League history to be substituted before half-time in three consecutive starts when he was replaced by Martin Zubimendi following a collision with Crysencio Summerville.
"He had a clash knee-to-knee and immediately he was uncomfortable," said Arteta in his press conference.
"I just spoke to him and he's not positive about it. He's got a brace on. We'll have to wait and see from the doctors."
Arteta was also downbeat about Rice, who was clutching his back when he made way for Mikel Merino in the 79th minute having opened the scoring with his first goal of the campaign.
"He's not alright because he asked me to come off, so that's a shame," said Arteta. "He had a pain in his back and he could not carry on, which is something very unusual for Declan.
"We'll have to assess him and see how he is."
Arsenal's injury list gets longer
Odegaard and Rice's injuries are just the latest to affect Arsenal.
The Gunners are already without Noni Madueke, Kai Havertz, Piero Hincapie and Gabriel Jesus, while William Saliba, Bukayo Saka, Ben White and Christian Norgaard have also had spells out this season.
Arsenal have suffered at least one injury in all but one of their seven Premier League games so far, with last weekend's 2-1 victory over Newcastle being the only exception.
The injury issues are a continuation of last term, when Arteta lost a string of key players for long periods, including Saka, Havertz and centre-back Gabriel, all of whom suffered hamstring problems.
Odegaard also missed a chunk of last season with an ankle injury and his latest setback, after being forced off by shoulder issues against Leeds and Nottingham Forest, is particularly frustrating following impressive displays against Newcastle and Olympiakos.
"We haven't had him since the start of the season for one reason or the other, the shoulder twice and then this injury," added Arteta.
"We have to wait and see the extent of that injury.
"We will find solutions but obviously our captain is at a place that gives us a completely different dimension with the things that he can do, especially in attack. Hopefully it's not that bad."
Depth crucial for Arteta
One positive for Arsenal is that their latest injuries come before the two-week hiatus for the international break.
Odegaard and Rice are due to report for Norway and England duty respectively but may instead have a fortnight to recuperate before Arsenal resume their Premier League campaign against Fulham, live on Sky Sports on Saturday October 18.
The squad's increased depth is another factor in their favour. When Odegaard went off, Arteta had the luxury of choosing from four potential replacements in Zubimendi, Merino, Ethan Nwaneri and Norgaard, with Zubimendi impressing after getting the nod.
Zubimendi and Norgaard were part of a £257m summer recruitment drive which has left Arsenal with what Sky Sports' Jamie Carragher has described as the best squad in the Premier League.
Even without Madueke, Havertz, Jesus and Hincapie against West Ham, Arteta was able to call on an exceptionally strong selection of substitutes, with Myles Lewis-Skelly, Ben White and the in-form Gabriel Martinelli also among his options.
"That's what we want but it's not ideal because we had really clear intentions with the line-up, what we wanted to do and that lasted very few minutes because of the injury to Martin," said Arteta.
"But the good thing is we can bring on somebody else and be a little bit different but still very efficient."
The latest setbacks demand further investigation as the club try to resolve their injury issues. But, top of the Premier League despite the absences, their depth is already making a difference.
