I would fully accept what he says there if Obertan produced Jonas like defensive performances, the truth is, from what i have seen of him, he's naive, weak and bottles challenges when we're not on the ball. He put in one totally out of character challenge near the touchline but there's no been no other instances where I've thought he was doing a good defensive job.
In my opinion, we should be going out looking to win games, especially at home. That means Ben Arfa starts, if Obertan comes on later to provide some more tracking back, then that's logical, but I think Pards is being over-conservative in the Ben Arfa/wing role issue.