I'm seen him pitch all year long and I think its a case of just being worn down. It reminds me of what happend to Vazquez when he joined the Yankees. Vazquez was throwing 95 MPH with the Expos and all of a sudden hes a Yankee and he has the velocity of Mike Mussina. Its not suprising that it happend right after Vazquez threw 230+ innings. Vazquez has never been the same since.
Garcia has been an innings eater over his career and I think those innings are coming back to haunt him because he is throwing 88-90. Not the 93-95 he once threw.