Adrian Lopez is waiting on the results of a scan on his injured hamstring but Wigan Athletic manager Roberto Martinez believes he will be out for between six and ten weeks.
The Spanish defender suffered the problem in the closing stages of Saturday's 2-1 loss to Norwich City but carried on until the final whistle as Martinez had already used his three substitutions.
The extent of the damage has yet to be confirmed but Martinez has admitted that he fears the worst.
"We are waiting on the results of another scan, but Adrian has a tear to his hamstring and it will probably be between six and 10 weeks," he told the Evening Post.
"It's a shame because Adrian has never had a soft-tissue injury before.
"He is a sprinter and he has a real sprinter's muscles - and you don't usually see people like that picking up this kind of injury."
While Wigan could be without Lopez for a couple of months, they have received better news on James McCarthy after scans cleared him of ankle ligament damage following a challenge by Bradley Johnson.
Martinez is not yet sure whether he will be available for the weekend clash with Arsenal, but is thankful there is no serious problem.
"You knew it was a bad injury straight away because he got caught right on the ankle, and James' reaction was completely understandable," said the Wigan boss.
"He knew he was hurt and he tried to stay on the pitch - and he wanted to play the second half as well but the injury was too serious.
"We've had the scan and he has a sprain in his ankle, and we need to see how that develops.
"Any sort of injury is disappointing, although we are relieved that it is not a really bad tear to his ligament."
No rushing back
Martinez added: "He's been working really hard this past two days, accelerating the recovery process, but it's too early to tell if he'll be okay for the weekend.
"It's always a worry when a player has to come off during a game but, knowing James, his recovery period will be a lot shorter than most other players.
"He hasn't rejoined the group yet - he'll be doing his own training routine for the next couple of days - and it will probably be Friday before we find out whether he'll be all right to play."
There is even a chance that Gary Caldwell, Antolin Alcaraz and Ivan Ramis could all be back in contention for the game against Arsenal following injury lay-offs.
"None of the three have rejoined the group yet but they are all stepping up their recovery programme," he said.
"At the moment I don't know if any of them will be available, but what is sure is that we won't be rushing them back.
"It would be very wrong for us to rush a player back and then risk losing him for a much longer period."
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