Arsenal have been handed a fresh fitness concern before Sunday’s clash with Chelsea after Bruno Guimarães and Cristhian Mosquera were both absent from Thursday’s first-team training session.
The £75million summer signing only recently returned from a groin problem and made his Premier League debut from the bench during Arsenal’s 1-0 victory at Aston Villa.
talkSPORT reported from Arsenal training that neither Guimarães nor Mosquera was involved with the main group on Thursday. Declan Rice did train, while Jurrien Timber continued individual work.
Importantly, Arsenal have not confirmed that Guimarães has suffered another injury.
🚨JUST IN! 💣
Bruno Guimarães and Cristhian Mosquera ABSENT at Arsenal’s open training session this morning. 🇧🇷 🇪🇸 ❌
ℹ️ @SamBIitz
— AFC Xtra (@AFC__Xtra) September 3, 2026
Bruno Guimarães gives Arteta fresh Chelsea concern
Guimarães missed Arsenal’s opening league win over Coventry because of the groin issue before returning to Arteta’s squad at Villa Park.
The Brazil international was introduced from the bench but has yet to make his first Premier League start for Arsenal.
His Thursday absence therefore raises an obvious question ahead of Chelsea.
Arsenal have enough midfield depth to cope if Guimarães is unavailable, with Declan Rice, Martin Zubimendi, Myles Lewis-Skelly, Mikel Merino and Martin Ødegaard among Arteta’s options.
But Sunday’s fixture looked like a natural opportunity for the £75m midfielder to make his first league start.
That possibility is now less certain.
Our Arsenal predicted XI vs Chelsea already explains how Guimarães’ availability could alter Arteta’s midfield selection.
Mosquera also absent before Chelsea
Mosquera is another player to monitor.
The centre-back was forced off during the second half at Aston Villa after feeling a muscular issue.
Arteta initially played down the problem, saying Mosquera felt as though something could develop if he continued rather than confirming a significant injury.
His subsequent absence from Thursday training means the situation remains unresolved.
We are tracking the full defensive picture in our latest Arsenal injury update.
If Mosquera cannot start, £55m summer signing Ezri Konsa could make his first Arsenal start against Chelsea after replacing the Spaniard at Villa Park.
Rice hands Arsenal some positive news
There was at least encouragement surrounding Rice.
The England international was involved in Thursday’s session despite appearing uncomfortable towards the end of the Villa victory.
Timber was also back working on the grass, although he remains away from full group training.
With William Saliba already unavailable, Arteta will hope Mosquera’s absence is precautionary rather than another significant defensive setback.
Chelsea arrive at Emirates Stadium on Sunday with both clubs having won their opening two Premier League matches.
Supporters can find the kick-off time and broadcast information in our Arsenal vs Chelsea viewing guide.
For now, Guimarães and Mosquera are simply fitness doubts rather than confirmed absentees.
Arteta’s next update should give a much clearer indication of whether either player can feature.
Arsenal injury news: Mosquera boost as Saliba and Timber set to miss Chelsea
Arsenal injury news: Mosquera boost as Saliba and Timber set to miss Chelsea