Further examinations show a dislocated shoulder
Moses suffered a shoulder dislocation in Tuesday’s game against Arsenal after landing awkwardly.
Manager Roberto Martinez described the injury as a “huge setback” for the team as they attempt to claw their way up from the bottom of the table.
Since his move from Crystal Palace to the DW Stadium last January, the 19-year-old Nigerian has made his mark with the Latics, recently establishing himself as an integral part of the team for the club and fans.
Originally, Moses was expected to return within four weeks of the injury, but initial optimism quickly turned to Moses and Martinez's worse fears.
“We haven't got the final assessment but we fear the worst,” declared Martinez to ESPN Soccernet.
“It seems it could be the best part of three months that we are going to miss Victor. It is a real blow.
“He has worked hard to earn his place in the side and he has done that with real style. You could see slowly he was imposing himself.
“Now he has been knocked back by an injury but we will make sure he comes back ready to have big say in the final three months of the campaign.”
Other problems Martinez is facing ahead of Saturday’s clash against Stoke City includes James McCarthy’s knee problem, Hugo Rodallega’s suspension and a fresh doubt for Franco di Santo.