Arsenal have been dealt a fresh injury concern ahead of their Champions League quarter-final second leg against Real Madrid, with Ben White left out of the squad for Saturday's Premier League clash with Brentford.
White, 27, was a surprise omission from Mikel Arteta's matchday 20, with the Arsenal boss confirming the defender 'felt something again post-training yesterday' and was not risked.
It is unclear if the issue is related to the knee injury that kept him sidelined for 25 games earlier this season.
The former Brighton man returned to full training in February following knee surgery and had featured in six of Arsenal's last nine matches prior to Saturday's fixture at the Emirates.
His most recent appearance came in midweek when he was introduced as an 89th-minute substitute in Arsenal's emphatic 3-0 win over Madrid.
Arteta now faces a nervous wait to see whether White can recover in time for the return leg at the Santiago Bernabeu on Wednesday, where Arsenal will aim to protect their three-goal advantage and book a spot in the semi-finals.
White's absence was compounded by the unavailability of Jurrien Timber.
That forced Arteta to deploy midfielder Thomas Partey at right back against Brentford - a makeshift solution that may not suffice against the threat of Vinicius Junior in Madrid.
Speaking ahead of kick-off on Saturday, Arteta said: 'Ben White couldn't be in the squad because he felt something again post-training yesterday, so that limits the solutions we have because Jurrien wasn't ready to start the game either.
'Other players as well played a lot of minutes and other players deserve to play minutes to help the team.'