I'm still not convinced by the Robles in matches, to be honest. He looked good against Norwich (although not much better than Howard did against them) and Middlesbrough (a Championship club resting the majority of their starters), but only adequate against Reading (another Championship side) and downright awful against Barnsley (a League One side). Five goals conceded in four matches, mostly against lower league sides, doesn't exactly fill me with confidence. Neither does the run in the side last season; even though it culminated in those three clean sheets, we only won one of the eleven matches he played in during that stretch.
The idea that the defense trusts him more than Howard seems like conjecture, too. He's certainly better than Howard at claiming crosses (although he's had his share of flaps in his career, too), but I haven't seen anything that makes me think the defenders are any less likely to make bonehead mistakes with him in goal than with Howard. I still can't get that Barnsley match out of my head, and I doubt Martinez can, either.