I'll point out that Nasri's contract with MCFC runs through June 2019. He could end his loan at Sevilla, play a full season here on loan, and still be sold by MCFC if it doesn't work out efficiently.
EDIT: I mean 1.5 seasons here. Second half of 2017 and all of 2018.
I would not be surprised to see Nasri in the summer. He has made no secret of his desire to play in the MLS.