Arsenal have suffered major injury blows ahead of their Premier League match against Chelsea at the Emirates Stadium on Sunday.
It has been reported that Bruno Guimaraes and Cristhian Mosquera were absent from training on Thursday.
During an open training session on Thursday, the media quickly noted the absence of the two players.
Both have been struggling with injuries recently and may not feature in the upcoming match against Chelsea.
Guimaraes had previously dealt with a minor groin issue earlier in the summer but managed to play in the FA Community Shield victory over Manchester City.
He missed the opening match but came off the bench in the win against Aston Villa, contributing for the final 20 minutes.
Arteta addressed his concerns regarding injuries earlier in the summer, stating: “We expect that not to be weeks at all. Let’s see how he evolves this week.
“He didn’t even want to stop. He wanted to carry on. Now we start to understand the character of the player, but I don’t expect that to be a big issue.”
It is still uncertain whether Guimaraes is experiencing the same issue again or whether he was simply absent from training as part of his recovery.
Meanwhile, Mosquera has become the latest defender to sustain an injury for the Gunners.
The young defender left the field injured during the victory over Aston Villa, with Ezri Konsa stepping in as his replacement.
The Gunners are already missing William Saliba and Jurrien Timber. Although the Dutchman has returned to light training, he has not yet regained sufficient fitness to be included in the matchday squad against Chelsea.
For Chelsea, the Blues also have injury concerns, with Moises Caicedo and Marco Palestra unlikely to make the trip across London.
Both players have struggled with injuries this season and were not seen in training ahead of the Arsenal clash.
Caicedo came off the bench in the win over Brighton & Hove Albion but played just 11 minutes before going off injured again.
Xabi Alonso has revealed that it is a minor knee issue, which also kept him out of the wins over Fulham and Luton Town.
Palestra has not played a single minute since pre-season and is yet to make the matchday squad this season. He joined the Blues this summer from Atalanta, and Alonso has not revealed the nature of his injury.