Manchester United have been hit by a massive blow as striker Robin van Persie is reportedly set to be out of action for at least a month after damaging his ankle ligaments.

According to the Mirror, the Dutch striker, who picked up the injury during Manchester United's 2-1 loss to Swansea City will be missing for United's crucial FA Cup quarter-final clash against rivals Arsenal.

The former Gunners striker picked up the injury late in the second-half of the game, but had to play on till the end as Louis van Gaal had already made all three substitutions.

This injury blow comes at a time when the Old Trafford club are entering one of the most crucial phases of the season and with Radamel Falcao's woeful form and James Wilson suffering a dead leg in a youth game, the manager will be short of options in the striker's department.

United are in contention for a place in the top four and are currently in fourth place, one point behind Arsenal in third and a point ahead of Southampton in fifth.

But they face crucial fixtures against Tottenham and Liverpool this month and both teams are breathing down the 20-times English champions' neck for a place in the Champions League next season.

Apart from the crucial Premier League fixtures, Van Gaal's team also have an FA Cup quarter-final showdown with Arsenal, and the report claims that the striker is certain to miss the clash. The competition represents United's only hope of picking up a trophy this season.

After a stunning debut season for the Red Devils, which included 35 goals, Van Persie is struggling for form and fitness this campaign and has netted just 10 goals thus far.