Roberto Martinez has labelled Fulham's tackling as "horrific" after Mohamed Diame was forced off after just 10 minutes of their 2-0 defeat on Saturday.
The Senegal international suffered two blows to the ankle in quick succession in challenges by Zdenek Grygera and Steve Sidwell.
Latics boss Martinez is awaiting the results of a scan on the injury and hopes Diame has not suffered serious damage.
Martinez told the Wigan Evening Post: "The injury to Momo was really disappointing.
"He had two horrific challenges in the space of about 30 seconds, really early in the game and it was just something where I don't think the referee gave any sort of protection.
"He was very fortunate with the first one, not so lucky the second time.
"We're hoping it's just a twisted ankle, after a really bad tackle. It's hard to tell at the moment though; we'll have to see how it develops.
"He'll have a scan to discover the real damage and if it's a ligament tear as well. If it is, it's going to be a really long period."