Ex-Germany coach Rudi Voeller has backed Bastian Schweinsteiger to play at least two more years of top-level football, despite having been frozen out at Manchester United by manager Jose Mourinho.

"Regardless of where his future lies, Bastian will keep playing at the highest level for at least two more years," Voeller, sporting director at Bayer Leverkusen, told German daily Bild on Sunday.

Just a year after joining United, Schweinsteiger, 32, has fallen from favour and was banished to United's reserves by new manager Mourinho, who has made it clear the German has no future at Old Trafford.

The Red Devils hope to sign Paul Pogba from Juventus before the current transfer window closes on August 31 and there have been reports that Schweinsteiger could move in the opposite direction as part of that deal.

"The manager decides his squad and decides a certain number of players for the season. That's it. I had to make my decision," Mourinho said on Schweinsteiger, adding that United hope to close the Pogba deal in time for the start of the Premier League season next weekend.

Schweinsteiger's ex-club Bayern Munich have said they are not planning to bring the former Germany captain back to Bavaria.

Voeller, 56, was Germany coach from 2000 until 2004, the year he gave a debut to Schweinsteiger, who went on to captain his country, scoring 24 goals and winning 120 caps before retiring last month.

Voeller points to Bayern's club captain Philipp Lahm, also 32, who he says has been helped by his decision to retire from international football after Germany won the 2014 World Cup.

"It will help him (Schweinsteiger) that he is no longer in the national team, at some point it would have been too much," said Voeller.

"It will do Bastian good that the amount of matches he will have to play will drop off. Philipp Lahm is a good example of that."