Radamel Falcao will definitely leave Manchester United this summer and could be followed out of the Old Trafford exit door by Robin van Persie, according to former defender Paul McGrath.

Colombian international Falcao has endured a hugely disappointing first campaign in English football, starting just 12 games in the Premier League under Louis van Gaal and generally struggling to display the sort of form that led to him becoming one of the most widely revered strikers in world football during prolific spells with Porto and Atletico Madrid.

Such a chronic lack of consistency has led to speculation that Manchester United will reject the opportunity to upgrade his season-long loan from Champions League quarter-finalists Monaco into a permanent deal this summer, with most believing that there are better alternative options who will likely be available for a far cheaper price.

Van Persie, meanwhile, began his own Manchester United career wonderfully following a controversial move from rivals Arsenal in August 2012. He won the Premier League title during his debut campaign at the club and also collected the Golden Boot award for the second successive season after notching 26 goals in just 38 appearances to ensure that Sir Alex Ferguson's glittering managerial career ended on the best possible note.

2014/15 was less successful for Van Persie, however, as he suffered from a variety of injury problems that ultimately proved detrimental to David Moyes' hopes of succeeding at the club.

Indeed, the 31-year-old has been similarly restricted this term and McGrath believes he could also be deemed dispensable despite his close relationship with Van Gaal that dates back to the latter's time in charge of the Netherlands national team.

"Without a doubt, he'll be gone," McGrath, who became a popular figure among supporters during a seven-year stint at Old Trafford in the 1980s, responded during an interview with talkSPORT when questioned on the future of Falcao.

"Robin Van Persie might be off as well, even with the Dutch connection with Van Gaal."

Van Persie has not featured at all for Manchester United since sustaining a knock to his ankle during the 2-1 defeat to Swansea on 21 February but should feature again in the coming weeks after confirming that he has now returned to first-team training.

The Red Devils are currently on a run of five consecutive top-flight victories and welcome City next for the latest Manchester derby just days after overtaking them to rise to third in the table.

United lost the reverse fixture 1-0 at the Etihad Stadium in November, but McGrath believes they have what it takes to avenge that defeat with Van Gaal at the helm.

"Man United are on a roll at the moment," he added. "Louis van Gaal deserves so much praise for it really. They have played badly for quite a lot of the season, so much so I didn't think they'd get into the top four this year, but he's done an amazing job.

"For them to be where they are now is incredible. I believe they'll beat Manchester City on Sunday as well."