Reyes IS playing with a sore hamstring, and it's been a problem for quite a while apparently. I don't know if you've ever pulled a hamstring, but starting and stopping fast really sucks. Anyhow, he's putting up 2.5 WAR even with the lack of defense and drop from base running. He's not even close to this team's biggest problem. Of course it would be nice if he was making closer to 15M per for the next few years instead of 22M, but it's not like he's pulling a Vernon Wells or Ryan Howard.
I also believe that the defensive ratings don't properly account for the turf. That'll hopefully change next year with the full rollout of mlbam.
As for Saki, he's rated as positive defense, just not as good as Goins.
For a final musing, what the hell has happened to Escobar's defense this year???