Arsene Wenger has revealed that Kieran Gibbs has suffered a setback in his recovery from a hernia operation.
The 22-year-old fullback has been sidelined ever since being forced to undergo surgery in November.
It had been hoped that the England international would be back in time for Wednesday's match against Aston Villa, but his struggle to regain match fitness looks to continue further.
"Kieran Gibbs has unfortunately had a setback and he is not back yet," Wenger told the club's official website.
"It's very disappointing because we had good hope that he would be back for tomorrow's game, but he is not available."
Gibbs is a product of Arsenal's academy and joined in 2004.