Arsenal defender William Gallas has suffered a setback in his recovery from a calf injury and could face another month on the sidelines.
The France international has not played since last month's 1-0 victory against Liverpool at the Emirates Stadium but has broken down in training and may miss be forced to sit out the rest of the campaign.
Gunners boss Arsene Wenger said: "Gallas has been out for a month and now he has had a recurrence of his calf injury.
"He felt very well on Sunday and went out but he has gone backwards again. We are at the starting point with Gallas unfortunately.
"At the beginning, it was a minor injury. We don't know how long it will be but for Hull, for example, he has no chance.
"We were impatient with him, we pushed him and he wanted to get on as well; that is why, maybe, it has happened.
"But there is no obvious sign as to why it keeps coming back. He has no pain at all, then he goes for a little jog and it goes again."