LONDON -- Arsenal manager Arsene Wenger has said Hector Bellerin's poor form is due to the lingering effects of an ankle injury, saying fan criticism of the right-back is unfair.
Bellerin has struggled in recent games as Arsenal have fallen out of the Premier League's top four.
The Spaniard was singled out for criticism by fans after last Monday's 3-0 loss at Crystal Palace, with some supporters chanting "you're not fit to wear the shirt" as he took a throw-in their section of the ground.
But Wenger, speaking ahead of Monday's game at Middlesbrough, said: "He has not come back to his level since he has been injured.
"I think for a while he was [still feeling pain], yes. Then you get bad habits and you forget that your job first is to defend and win challenges because you protect yourself a little bit.
"Then you realise you have to come back and I think now he is trying to focus again on what is important, to defend well and afterwards he can give us that extra bit that is important as well.
"I agree that for a while he was not the Hector Bellerin we had seen at the start of the season."
Bellerin missed more than a month after taking a kick to the ankle against Tottenham Hotspur in November, and was sidelined for another three weeks after being injured in training in January.
He has been a regular starter since his return, however, with backup right-backs Mathieu Debuchy and Carl Jenkinson both out of favour.
Debuchy and Jenkinson both played for the under-23s on the day of the Palace defeat, with centre-back Gabriel Paulista having filled in for Bellerin when he was injured.
Asked whether it was unfair for fans to turn on Bellerin, Wenger said: "I think yes, as he is guy who is genuinely Arsenal and wants to do well. He is ready to play with pain and I think it is [unfair]."
However, Wenger said Bellerin had now completely recovered and there was no risk of him needing surgery.
The player has been a transfer target for his boyhood club Barcelona but signed a six-year contract extension with Arsenal this season.
He is likely to be called up for this summer's European U21 Championship in June and Wenger said: "It's not ideal after a long season. He should have a rest and prepare for next season.
"The Spanish players love to play for their country, and I think he will go as he loves to play for Spain."