I think his positional awareness is a lot better than people give him credit for.
Just because he doesn't tackle like Nigel de Jong doesn't make him a bad player. Xabi Alonso said a while ago that he doesn't understand the British obsession with tackling.
In Spain tackling should be seen as a last resort and the fact you have to make a tackle can be indication of doing something wrong rather than something right with regards to reading the game. One of the best defenders of all time Paolo Maldini only made 1 tackle every couple of games.
Because there's a bias between what is obvious visually (e.g. a tackle) and what is harder to see (slight movements and blocking passing channels, for example), players such as Garcia can be castigated.
The problem is when he does get things wrong tactically occasionally (like away at Wigan in one of his first starts for us) then that will be ingrained in people's minds and the good stuff gets ignored.
I believe he will be very useful for us next season. Maybe I'm wrong, we shall see.