Wigan midfielder Ben Watson suffered a broken leg in his team's 3-0 defeat at Premier League rivals Liverpool, Latics boss Roberto Martinez has revealed.
The first half was stopped for almost five minutes as Watson, 27, received treatment after challenging for a high ball with Reds winger Raheem Sterling.
"It is a broken leg and we will see the extent of the break and what treatment he needs," said Martinez.
"Both were looking at the ball - it's a real accident. It's a nasty collision."
Former England Under-21 international Watson collapsed to the Anfield turf clutching his right leg shortly after the half-hour mark of Saturday's Premier League match.
But he waved away the help of a stretcher and limped off with the support of Wigan medical staff.
The match was goalless when Watson's departure forced Martinez into a reshuffle, before the Latics succumbed to three second-half goals by the hosts.
Martinez added: "The injury affected us too much. We are really going to miss him. He has got a fracture.
"We are going to assess him now, maybe he needs surgery. It is too early to tell [how long he will be out for].
"We are really disappointed because Ben reached a really, really good level and today you could see that every time he got on the ball we were very penetrating with his quality."
Watson, who joined the Latics from Crystal Palace in a £2m deal almost four years ago, has made eight Premier League appearances for the Latics this season.