I am not 100% sure but if he only played 11 games for his former team he will lose his top-10-position at the end of the season because the minimum number of required games is 12.
So at this point he stays in the top-10 because he made 11 of 10 required games.
From my understanding you receive the top-10-merch for him now but you will loose this and receive your own top-10-merch as soon as he played enough games for your team.
founded in S3 IV.5 (34234) - returned in S28 IV.7 (34515)