Louis van Gaal deserves to see out the final year of his contract if he can win the FA Cup, former Manchester United midfielder Roy Keane has said, amid a report that Jose Mourinho may have to wait a year to take over as manager.

Van Gaal is nearly two years into his three-year deal at Old Trafford, but there has been regular speculation that he will leave the club at the end of the season, with sources telling ESPN FC last week that Mourinho remains eager to take the job this summer.

The Dutchman faces an uphill battle to secure Champions League qualification for next season but he has guided the club to the FA Cup final, where they face Crystal Palace.

Keane, who spent 12 years at United under Sir Alex Ferguson, said it was inevitable that the club take time to get back on track after the Scot's retirement in 2013 and that he hopes Van Gaal is given the chance to continue his work next year.

"It was always going to be difficult, even for David Moyes, after Alex Ferguson, but I think if United can win the cup -- it might be difficult to finish fourth -- I don't see why United won't let him finish out the last year of his contract," Keane told podcast "Beyond the Pitch."

"I think Van Gaal has made it clear he'd like to do that, and I hope he does.

"I don't like sitting around watching managers suffering and I think if they can win the FA Cup then it might just give him the breathing space to finish the job off next year -- and that, when we're talking about Manchester United, is winning league titles, et cetera."

Louis van Gaal led United to fourth place last season but faces a tough test to return to the Champions League. Clive Brunskill/Getty Images

There have been suggestions more recently, including from Van Gaal himself, that he will be given the chance to see out his deal, and The Sun reported on Thursday that executive vice-chairman Ed Woodward has asked Mourinho to wait 12 months before taking the job.

United are likely to bolster their squad in the summer regardless of who is in charge and Keane said that, although they do not need to "rebuild," they need to bring in strong characters to cope with the growing competition at the top of the Premier League.

"Rebuild is too strong a word but there's a lot of hard work ahead for Man United because of the competition around," Keane, currently working as Ireland's assistant manager, said. "Leicester coming through, Chelsea will be stronger next year, Man City with a new manager.

"It's not going to get any easier for United but if they're going to recruit again this summer -- which it looks like they'll have to -- whatever about getting good players, United probably need two or three characters in the team so that on their bad days they're capable of grinding out results.

"I just think they don't have enough characters in that team to get them back to winning league titles at this moment."