Former Manchester City striker John Guidetti has said that knows all too well about the importance of beating Manchester United as he prepares for Celta Vigo's Europa League semi-final against Jose Mourinho's side.

Guidetti spent six years at City, but he struggled to cement a regular spot in the senior team and after numerous loan spells left to join Celta in 2015.

The Spanish club will host United at the Balaidos on Thursday before travelling to Old Trafford for the semi-final second leg on May 11.

"[United are] a very good team," Guidetti told UEFA.com. "Obviously they've got a good manager, a fantastic stadium, and they're one of the favourites to win the Europa League but, as they say 'Manchester is blue' and that's how it will be when we visit there as well, because we are Celta Vigo and we will try to keep the city blue."

United's best hope of securing a Champions League spot this season could be winning the Europa League.