Manchester United forward Zlatan Ibrahimovic has suffered serious ligament damage in his right knee and will likely be sidelined until at least January 2018, sources have told ESPN FC.

The 35-year-old underwent scans in Manchester on Friday after sustaining the injury during United's Europa League quarterfinal victory against Anderlecht at Old Trafford on Thursday. The initial fears of manager Jose Mourinho and the club's medical staff have been confirmed.

The prognosis for Ibrahimovic, who has scored 28 goals in 46 appearances for United since arriving on a free transfer from Paris Saint-Germain last summer, is surgery followed by a programme of rehabilitation. However, Ibrahimovic is not expected to return to action this year.

The injury has placed doubt over his club future; his United contract is due to expire at the end of this season.

Zlatan Ibrahimovic fell awkwardly before leaving Thursday's match with Anderlecht. Matthew Ashton - AMA/Getty Images

Mourinho has said that Ibrahimovic has passed all of his performance-related criteria to trigger a one-year option in his contract, but the forward has so far not committed to a new deal at the club. Ibrahimovic has also played for Juventus, Ajax, Inter Milan, PSG and Barcelona.

Sources at Old Trafford have been unable to confirm to ESPN FC whether United are now under an obligation to give Ibrahimovic the extended contract after his injury.

Ibrahimovic had been the subject of interest from MLS clubs LA Galaxy and LA FC, the latter of which will launch in March 2018, but his spell on the sidelines has cast uncertainty over a potential move to the United States.