London: Manchester United fear that the career of Zlatan Ibrahimovic could be over after their star striker suffered "significant knee ligament damage" during last Thursday's Europa League game with Anderlecht.
Old Trafford sources have indicated that the physical damage - he tore both the anterior and posterior cruciate ligaments of his right knee - raises fears that the 35-year-old will have to retire from football.
Medical examinations on Friday confirmed the double rupture - an extremely rare injury for a player of his age. The predicted recovery period is nine months to a year, but experts within the club believe that even if his reconstructive surgery and rehabilitation work go to plan "he will not play again at this level".
"With a double cruciate rupture it could easily take a full year to reach 'performance' level," a leading Premier League physiotherapist said. "Ibrahimovic's issue will be whether he has enough time after his injury to get back to a normal rhythm of playing. He's as old as any player I can think of to have done this."
The striker is United's top scorer this season with 28 goals but is out of contract at the end of the season. United hope to convince Antoine Griezmann to join them from Atletico Madrid in a deal that may require them to meet the France international's £83.7m release clause.
United are also monitoring - Monaco's teenage finisher Kylian Mbappe and Everton's Romelu Lukaku. A club statement released confirmed that defender Marcos Rojo would also miss the rest of the season with injury.
Ibrahimovic didn't have his finest game against Anderlecht - Marcus Rashford edging United through to the semi-finals on aggregate after extra-time - but his goals this season have been the main reason for an improvement in the club's fortunes, albeit without ever being title challengers.
Ibrahimovic has defied many doubters since joining on a free transfer from Paris Saint-Germain last year.
Rojo's injury is also a serious body blow to United's depleted resources at the back with both England international central defenders Phil Jones and Chris Smalling expected to be out till mid May.
