Evo that makes no sense. Injuries are NOT an excuse for poor performance. His awful first half should not be discounted in any way. If he was that hurt he should have went on the DL.
When did players start putting themselves on the DL? Besides, how would that even play out? What player is going to have himself put on the DL because he's got an injury he feels he can play through and isn't going to get worse? You don't blame him for that, you blame the training staff/manager/GM whoever, but not the player for letting him keep playing. As tenuous as a pro sports career is, I don't blame him for a single second for not wanting to give up his PT.
As for the Jimmy Rollins comparison, I think that was one of the issues that caused Desi quite a number of errors. He tried to make plays that weren't going to happen just because he got to the ball. He's shown now that he'll give up on a play and eat the ball as opposed to forcing a throw that could make the situation all that much worse. Through the first 30 games, Ian had 8 errors, in the 90 games since then, he's committed 13. I'd say he's done much better over the rest of the season. And fwiw, those 8 errors were committed with LaRoche at first.
I really don't see anyone here saying Desi is a great ball player, I think what most are doing is suggesting that we temper our enthusiasm for replacing a player with an unknown quantity. Might work out great, might not work out at all. A September call up won't hurt anyone, that's for sure, but it'll be a small sample size.