Am I crazy? I thought I remembered A-Rod being a pretty decent, if not very good defensive SS.
He was a lot smaller and more limber when he was a pretty decent SS. He was no adam everett with the glove, but he wasn't a derek jeter (bad) either.
SI's article talked about how he dropped weight, lost some fat and became less thick through the middle this offseason- perhaps less muscle bound as well. I don't think the guy playing 3b last year for the Yankees would have been a particularly effective SS, but I also don't think he would have butchered the position. This year, who knows.
You are also talking about an Alex Rodriguez today who is 3 or 4 years older than the ARod who last played SS, and 6 or 7 years older than the guy who played it, more or less excellently (based more on heresay than my actually watching him- but that's the way I remember hearing it) up in Sea