Arsenal defender Shkodran Mustafi has been ruled out for six weeks while Laurent Koscielny faces a late fitness test ahead of Saturday's Premier League clash with Watford, manager Arsene Wenger has said.
Alexis Sanchez, who saw his 2018 World Cup dreams crushed when Chile lost to Brazil on Tuesday, will join the group on Friday and Wenger said he would assess the striker's fitness.
Koscielny, on the other hand, skipped the recent worldwide break to recover from an Achilles injury that has been a long-standing issue for the France defender.
Obviously it will be a big boost for Arsenal to have the centre-back available for their crunch North London Derby but he's going to be sorely missed over the coming weeks.
Arsenal will be looking to maintain their winning run when they take on Watford FC in the Premier League this weekend.
If both defenders are unavailable, Wenger will have to turn to back-up options Per Mertesacker and Rob Holding to fill the void, as Calum Chambers also remains sidelined with a hip injury.
'He didn't play in their first game and we lost him in the second - we have to cope with that now'.
Wenger explained: "Koscielny has a definite final test tomorrow".
"The minor problem we have is with Sead Kolasinac". I think about sorting out the problem, but overall I will decide completely tomorrow the line-up because Koscielny will have a test.
Alexis Sanchez will not report back from worldwide duty with Chile until Friday, but Wenger has no concerns over the forward or Aaron Ramsey's mental state after their World Cup exits.