The rating takes everything into account. His game shape, offensive and defensive play.
No, thats not true!. It would not even make any sense. Those star ratings are all about the players contribution to the team. Its pretty good explained in the rules:
This rating is based on a combination of your player's stats and his overall contribution to the team effort. Note that this has nothing to do with the player's overall skill; if your worst player overall is the best on the court, he'll have the highest rating!The ratings are based on the contribution to the game. The better a players skill, the better his game shape, the more likely he have good contributions to the game => then he will get a good rating.
So the rating does not take into account the game shape but the contribution, however the contribution is a RESULT of his game shape and his skills.
My player had just receive ((2066728)) a rating of 3.5, but his stats were these:
Botero, Luis 48 4 - 7 1 - 1 0 - 2 4 19 5 2 0 2 1 9 3.5
I know didn't take enough shots for 48 minutes, but he took 19 RBs.
His stats are very good and his ratings looks very low. In my experience the rating takes the defensive performance heavily into account. I have a very good defender he is only producing average stats but he always get a good star rating. In contrary I have a player having about 15 pts per game, grabbing 12 rebounds but only getting 4 and 4,5 in the star rating. he is a pretty bad defender.
So I guess your player did defensivly a very bad job. If u have played Man to Man his oppenent scored probably much more than usual.
Another reason is that he might have played bad passes, producing a bad offensive Flow to your team.