The Swede's move to LA Galaxy was confirmed on Friday.
"What I have learnt from him is irreplaceable," Rashford said. “You will see the benefits in years to come. No other forward in the world could have come in and been able to pass on so much.
"There is nobody else that we could have learnt that much about football - and mentally – from. For me, it's the mentality he's brought with him that's the biggest thing I'm going to take from what he's offered us. His mentality alone is what puts him head ahead of the game. Before he's even kicked a ball on the pitch, in his mind he's already ahead of everyone else, and that's a massive mentality to have."