Arsenal boss Arsene Wenger shocked Manchester United decided to let Robin van Persie leave

Arsenal manager Arsene Wenger is surprised Manchester United allowed the "exceptional" Robin van Persie to leave the club.

The striker, 31, signed with Fenerbahce on Monday 13 July and while there is still no confirmation of a fee received from United, his arrival in the Super Lig was celebrated feverishly by the Turkish giants.

The Netherlands international spent three seasons at Old Trafford after leaving Arsenal, playing an integral role in the club's 2012-13 season where his 30 goals fired the club towards the Premier League title.

And despite his last two seasons being interrupted by injury, Wenger believes his exit is a loss for United and the Premier League.

"For me it is a big surprise," Wenger told a press conference from the club's pre-season tour of Singapore, the Mirror reports.

"I am quite surprised that Robin van Persie has gone to Turkey this summer. He is a loss for English football because he is an exceptional player, one of the best I have ever managed.

"He has exceptional technique. I don't know what happened or why he leaves United but he is a loss to the Premier League."

United manager Louis van Gaal has already shown his ruthless streak since being appointed manager at Old Trafford. The Dutchman has already told Brazilian full-back Rafael da Silva he can no longer count on him, according to the defender's agent, while Victor Valdes has been told he will be sold after failing to accept the manager's philosophy.

Van Persie's future came under real doubt following last season's injury-hit campaign, where he managed just 10 goals and failed to reclaim a starting role in Van Gaal's first team upon his return.

The striker spent eight years at Arsenal after being signed from Feyenoord in 2004 and received two footballer of the year accolades in 2012, one from the Football Writers' Association and the other from the Professional Footballers' Association, in what was his final season at the Gunners.