Mourinho confirmed that Madrid had received a number of offers for the 23-year-old Turkey international, with Liverpool and north London rivals Arsenal and Tottenham linked.
"The Premier League is a good place for players to pick up certain characteristics which he does not have," said Mourinho.
Sahin has had little game time since making his move to the Bernabeu 12 months ago and Mourinho is eager to farm him out to continue his development.
And the former Chelsea boss believes the English top flight is the best place for his young midfielder, regardless of the club.
"It is all the same to me, though, which club he goes to.," added Mourinho.
"I just hope that it happens soon for him, as it is best for him. Liverpool, Arsenal or Spurs - I have no preference."
While interest in Sahin is high, Mourinho revealed the club were yet to field an offer for Brazilian Kaka.
There had been reports Manchester United were interested in tabling a bid for the 30-year-old, but Mourinho denied that was the case.
"Kaka's situation is completely different," the Portuguese said. "We have no official request for Kaka; we do for Nuri."