Robin van Persie (L) and Sir Alex Ferguson
Robin van Persie (L) and Sir Alex FergusonReuters

Manchester United legend Rio Ferdinand believes the reason for the slump in striker Robin van Persie's form was the sudden departure of former manager Sir Alex Ferguson.

Ferguson was a key factor in convincing the Dutchman to switch from rivals Arsenal to Old Trafford for a reported £24m during the 2012 summer transfer window.

The Netherlands international joined United after having his best season in an Arsenal shirt and continued that form with the Red Devils, when he top scored for the second season in a row to hand the Manchester club their record-breaking 20th English first division title.

But it came as a shock to everyone when Ferguson announced his decision to step down as United manager at the end of the 2012/13 season. Ferdinand feels, even though his decision affected the entire club, it hit van Persie harder than anyone else in the team.

"It took the wind out of everyone's sails. It gave us an extra push to go and win be successful in that last season," Ferdinand said, as quoted in the Daily Mail.

"Everyone was really appreciative for what he'd done for our careers."

"The person it hit more than anyone was Robin. He'd come the year before, tasted that success and wanted more. Visually you could see it hit him harder than anyone else at the time," the Queens Park Rangers defender revealed.

Van Persie has since struggled in form and fitness and had a torrid season under David Moyes, who was brought in as Sir Alex's replacement at the club. But the Scot was sacked before the end of his first season in charge.

However, things have not improved following the arrival of his former Netherlands boss Louis van Gaal and United and the Dutch striker find themselves out-of-form, still struggling to get back to the top of the league they once dominated.