Do you really watch many PSV games or do you know him from the national team? My local favorite club is PSV and I have to say, he is good but not that good. He does have a good shot and a good free kick. But he isn't that great of a dribbler; he almost always goes to his right foot and moves inside. No action on the sideline and he isn't giving lots of balls to the CF/Striker. He is becoming quite predictable after a season, and it seems Dick Advocaat(coach PSV) isn't overly impressed by his contributions here and there. Finally, the worst thing is something you call good! His defensive contribution is awful, rarely covers for other players and is used to not marking his man. That really needs to improve if he wants to move to a bigger club in a bigger league. I think in a year, Memphis Depay has overtaken his spot in the first XI, he has greater speed, better technique and a better dribbling action. So much talent!
Mertens is limited to what he can do, because he plays his position as instructed, hugging the touchline to widen the game. It's the same as Iniesta when he is deployed wide on the left- he simply has less creative options than when he is more central. Mertens has even less because his teammates aren't as positionally adept as Barça, and make fewer smart off-ball runs, are less accurate on 1-2s, etc. Even so, as Mertens cuts in from the side of the box, he always has an eye for a far post runner or someone overlapping (like Alba) for a sharp cut through pass (and not to mention his excellent curling shots). I think you are interpreting PSV's limitations as Mertens'; I see it the other way around.
