Depends on the nature of the injury, his brief spell in the first team last year might have been premature return and done nothing but aggrevate it. He's officially listed as injured for just about every game we play these days, which is released by the club along with the team sheets each week. Canny see beyond that fact: if it says he's injured, then he's injured.
As for the lost interest idea... he's probably completely scunnered at being out so long and his head might be going down so it's easy to see how chinese whispers could turn that into 'lost interest'.