LONDON (AFP) - Arsenal midfielder Santi Cazorla has been forced to have another operation on his Achilles, prolonging his long injury nightmare and delaying his return to action.

The Spaniard has not played for the Gunners since October last year and said earlier this month that he almost lost his foot owing to a serious infection.

Manager Arsene Wenger had expressed hope Cazorla might recover in time to feature again in January but the 32-year-old has suffered a fresh setback.

"Due to some discomfort in the tendon the last few days, I have had to undergo surgery," Cazorla tweeted on Wednesday.

"It is delaying the date of my return to the field. I maintain my hope and motivation to enjoy my great passion, football."

The message was accompanied by a picture of Cazorla making a gesture of prayer while in action for Arsenal.

Wenger has admitted that the injury is the worst he has known, with the player's foot requiring a series of operations, as well as a skin graft from his arm.

Cazorla joined Arsenal in 2012 from Malaga and has made more than 150 appearances for the club.