Radamel Falcao
Louis van Gaal unsure of Radamel Falcao's fitness to play regularly in the Premier LeagueGetty

Manchester United manager Louis van Gaal has reportedly cast doubt on striker Radamel Falcao's Premier League future after questioning his fitness.

According to the Daily Mail, the Dutchman fears that the Colombian international's injury issues will hamper him from taking part on a regular basis in the league.

United signed Falcao on loan from AS Monaco on transfer deadline day, and reports are now claiming that the Old Trafford club have already sorted the details of making the move permanent with the Ligue 1 outfit. The fee agreed between the two clubs is said to be around £44m for the striker.

The former Atletico Madrid striker came to United following a severe knee injury that kept him out of the 2014 World Cup, and he has only started three times for the Red Devils this season.

Falcao is currently recovering from a thigh injury he picked up in training ahead of the Chelsea game last month.

The Colombian striker has so far managed to score just one goal and it is believed that Van Gaal is seeking vast improvement from the striker before he finalises his plans for the striker's long-term future at the club.

The club's other senior striker Robin van Persie has been struggling for goals and has seen his form drop since the start of the season. And with Wayne Rooney moving into a midfield role, the report claims that United will be in the market for a top-class goal scorer during next summer's transfer window.

However, with United paying Falcao close to a £1m per month, they will have to decide on whether to use those funds to find a new striker or to take a gamble on the Colombian, who is struggling with fitness issues and will be 29, by the end of the current season.