Per Mertesacker looks set to miss Arsenal's clash against Chelsea this weekend, reports the Telegraph.
The German international was forced from the pitch in the Gunners' 2-1 FA Cup semi-final win against Reading over the weekend with an ankle injury.
Now the World Cup winner faces a race against the clock to make it onto the pitch at the Emirates Stadium on Sunday.
Arsenal boss Arsene Wenger admitted after the extra-time win against Reading that the injury 'doesn't look good', and now the Telegraph's Matt Law claims that the German is looking increasingly likely to miss the game.
That means the highly-rated Gabriel Paulista will step into Mertesacker's place for the showdown against Chelsea having done so against the Royals. The Brazilian has so far played five Premier League games since his move in the January window from Villarreal, and has been tipped as a long-term successor to Mertesacker.
As it stands Arsenal sit 10 points behind Chelsea having played a game more - and Jose Mourinho's side can wrap up the title with a win on Saturday as well as three points against Leicester in mid-week.
If Arsenal, who are in second place, are to make anything of the title race they will need to walk away with a win against Chelsea, who are unbeaten in their last 14 games in all competitions and who go into the game on the back of a 1-0 win against Manchester United.
Meanwhile Arsenal midfielder Abou Diaby could be handed a pay-as-you-play deal to keep him in north London for next season.
The Frenchman's career has been ravaged by injury and it was expected that he would be allowed to leave in the summer. However the 28-year-old has reportedly impressed Wenger with his performances in the U21 team in recent weeks and could be handed a lifeline.
The Telegraph say that Wenger is willing to give him another chance to prove his worth before cutting him adrift.
Per Mertesacker is a much maligned figure at Arsenal but of late he's shown his worth - even if he doesn't have pace he has nous and intelligence which he uses to his advantage.
Gabriel Paulista isn't a bad alternative however and given how unlikely it is that Arsenal will be able to haul themselves into the title race then they really have nothing to lose.