The Wales international - who himself was a second-half substitute for Gabriel - was forced off after 73 minutes at the KC Stadium with an apparent shoulder problem
Aaron Ramsey has become the third Arsenal player to suffer an injury against Hull City after Per Mertesacker and Gabriel had both been forced off.
The Wales international was forced off after 73 minutes after seemingly suffering a shoulder injury and was replaced by Jeff Reine-Adelaide.
Ramsey himself was a second-half substitute for Gabriel who suffered an apparent hamstring injury while Mertesacker was replaced before half-time following a blow to the head.
The Gunners were already without Petr Cech and Laurent Koscielny for the FA Cup fifth round replay at the KC Stadium, and despite easing past the Tigers the trio of injuries is a cause of concern.
Arsene Wenger's side travel to Camp Nou to face Barcelona in eight days, while they remain in the Premier League title race despite some disappointing results of late.
- Goal