This was a test done with FM 2014 and may or may not be relevant in future versions.
I created a 100/100 CA/PA player and a 200/200 CA/PA player. Both are in the DC position.
The 100/100 player has 20 for each attribute and the 200/200 player has 15 for each attribute.
The 100/100 player has a coach report: Not good enough for the squad, good for the current competition, playing to full potential.
The 200/200 player has a coach report: Key player for the squad, world-class player, playing to full potential.
The coach has 200/200 CA/PA and 20 for each attribute including JA/JP.
When it comes time for match selection, with condition/fitness/jadedness/happiness/morale equal, the coach picks the 100/100 CA/PA player over the 200/200 CA/PA player. I did the test several times with the same result.
Therefore, I can only conclude attributes are the main criteria. Unfortunately, this means having to manually look at attributes and assess because the stars were handed out in line with the player CA/PA.
I don't mind the presentation the developer uses for coach reports but was hoping for at least the CA/PA stars to reflect the attribute part of the assessment for a fast answer.
The developer should make the CA/PA/Attribute triangle move together. When one increases/decreases the other does as well and gives an immediate answer.
