Wayne Rooney
Manchester United manager Louis van Gaal is unsure exactly when Wayne Rooney suffered his knee injuryGetty

Manchester United's faltering hopes of clawing back their place in the top four of the Premier League were dealt a significant blow on 17 February as news emerged Wayne Rooney has sustained a knee ligament injury. The club captain has not travelled to Denmark for the first leg of their Europa League last-32 tie against FC Midtjylland and reports estimate that he could be sidelined for up to two months.

If such gloomy estimates are true, then Rooney will miss a number of pivotal matches for United during the remaining weeks of the season. Louis van Gaal's fifth-place side, who currently sit six points adrift of Manchester City in fourth following a 2-1 defeat at Sunderland, host title contenders Arsenal on 28 February and also make the short trip to the Etihad Stadium for their local derby three weeks later.

They visit White Hart Lane for a date with Mauricio Pochettino and in-form Tottenham Hotspur on 9 April, although Rooney should presumably be back in contention for the clash with Leicester City on the last weekend of that month. In the likely event that United progress past Midtjylland over two legs, then the 30-year-old could be absent for both the round of 16 and the quarter-finals. He may also be reduced to a spectator's role for the last eight of the FA Cup, providing there are no shocks during next week's fifth-round trip to League One outfit Shrewsbury Town.

Rooney's injury would further appear to damage his chances of surpassing Sir Bobby Charlton's all-time goals record this term. He currently lies six short of the 250 needed to become United's top scorer after notching 11 times in all competitions since August, including an impressive run of seven in his last nine appearances.

Van Gaal will now rely upon summer signing Anthony Martial to shoulder an even bigger workload, likely supported by the unproven Will Keane. James Wilson could also be recalled from his loan spell with Championship promotion hopefuls Brighton and Hove lbion.

The impact of this absence will be keenly felt at international level as well. England skipper Rooney has a rather unfortunate injury record at major tournaments after cracking his metatarsal against Portugal at Euro 2004 and suffering a similar fracture just six weeks removed from the 2006 World Cup. He remains a pivotal member of Roy Hodgson's senior squad, having broken Charlton's Three Lions record in the 2-0 win over Switzerland last September.

Although this latest problem should not put his place in the squad for the upcoming European Championship in doubt, it is hardly ideal preparation and he would be forced to sit out the warm-up friendlies against Germany and the Netherlands in late March.