This picture was captured after the match was finished on 27 Nov. My GK was a 4 star player. Actually at that time he was a 4 star player just a sp away from 5 star and process 1 or more unassigned sp.
This picture was captured today for the same match. The same GK is now shown as 5 star player.
I just notice that the unassigned skill points of this player were finally suddenly automatically assigned and this made him becoming a 5 star player. I am not surprised by this and have no complaint. But it is interesting that the player is regarded as 5 star player for previous matches.
Not sure if this is a bug.