Radamel Falcao
Falcao has netted just four goals for United this season.Getty Images

Radamel Falcao's struggles at Manchester United failed to abate after the former world footballer of the year nominee was substituted after 72 minutes of the Under-21 Premier League draw against Tottenham Hotspur at Old Trafford.

Falcao was unable to make an impression in his first appearance at any level for the club since February against a Spurs team which had the combined experience of one senior appearance for the club.

Having not featured in the FA Cup quarter-final defeat to Arsenal, Falcao started the game but was replaced by James Harrop for the final 17 minutes after a dismal showing which included a miss-kick from point blank range and the ignominy of blocking James Wilson's goal-bound shot in the first half.

The performance, not least his inclusion in the second tier league match, will draw major questions over Falcao's long-term future at United, which while a decision will not officially be made until the end of the season, is increasingly looking like it will end with the 29-year-old's return to Monaco.

Reports suggest that United will require £44m to sign Falcao on a permanent basis this summer but having netted four goals this season the former FC Porto and Atletico Madrid hitman is rapidly running out of time to earn a contract with the 20-time English league champions.

While Falcao's career threatens to fizzle out at United, full-back Rafael attempted to reignite his own future prospects in the eyes of manager Louis van Gaal with an impressive showing against Tottenham.

After Kenny McEvoy had given the FA Youth Cup semi-finalists the lead after 26 minutes, Rafael equalised with a fine lob from outside the box after he intercepted Luke McGee's throw out to draw the hosts level.

Rafael was a constant thorn in the Tottenham side throughout his 90-minute run-out and gives Van Gaal food for thought ahead of the remainder of the season and a summer transfer window which was expected to see the 24-year-old leave the club.

The right back has started just six Premier League games this season and has played just once since October. Such has been van Gaal's lack of confidence in Rafael that he has preferred Antonio Valencia in his back four in recent matches ahead of recalling the Brazil international.

Combined with his fine showing against Tottenham, Valencia's error which saw his backpass intercepted by Danny Welbeck and led to Arsenal's winner in the FA Cup could yet represent a way back into the first team for Rafael.