This comment and some of the others on here about his performance in that game are simply insane. We don't need him to be David Alaba, we don't need him to take over and be our next Leighton Baines and make the World XI, we just need him to play left back for a few games. The Norwich game performance shows that he can hold the ball up, pick out an intelligent pass, find players with long balls on the break, cross the ball and track back to defend. It doesn't say much about his defensive ability, but only someone like Martinez who sees what he's capable of on the training ground will be able to make that determination.
And to the point about Mirallas, if he had made that assist I would have taken it as a piece of evidence supporting the claim that he deserves to play, and I take it the same way for Oviedo.
Gareth Barry has arguably been our most important player this season playing in the centre of the pitch, it would be exceedingly dumb to move him out of position because Oviedo hasn't proven that he's world class in ~3 chances.
If Martinez chooses to leave him out of the team, I'll trust his judgment and assume there are weaknesses to his game that we don't get to see. But none of you actually know that, many just seem perfectly comfortable assuming he's garbage despite little evidence to support that, and slightly more evidence to the contrary.