Paul Scholes has said it could take another "18 months to two years" for Jose Mourinho to build a Manchester United team that can challenge for top honours after watching his former club slump to defeat against Fenerbahce.
Moussa Sow and Jeremain Lens scored to give Fenerbahce a 2-1 win in the Europa League Group A clash in Istanbul, with Wayne Rooney scoring a consolation goal for the visitors.
The Red Devils have only won two of their last seven matches in all competitions and are eighth in the Premier League, eight points behind leaders Manchester City.
"It's been quite a painful three years," Scholes was quoted as saying by ESPN.
"And I think the next 18 months to two years could be very similar until this manager has three or four transfer windows to really get a team that he wants.
"I think this team in two years will be unrecognisable from what it is now. But, whatever we can do in these two years has to be a bonus; whether they can win the League Cup whether they can win the FA Cup.
"Can they win this competition? It doesn't look like it. And it has shown in the last three years that they are not capable of winning the league with this squad."
United are third in Europa League Group A, one point behind Feyenoord and Fenerbahce. They host Feyenoord at Old Trafford next before travelling to Ukraine to face bottom club Zorya Luhansk.
Scholes said United had to step up their level of performances if they are to finish in the top four this season.
"United have two big problems at the minute," he said. "They're really struggling to score goals and to win games of football with [Daley] Blind and [Marcos] Rojo at centre-half they almost need to score three goals because they look like they're going to give goals away all the time.
"They don't sense danger, they've got no pace, they don't get physical against people. And it's a worry because at the other end they really don't look like scoring goals."