The degree of his injury is reported to take 2-3 weeks to recover. He himself is saying he is getting better each day, so he shoudl be 100% by week 3, at worst week 4, which is when we really need him, which is against the Rams.
I would run him to the ground as well. His injury consists of a half torn plantar fascia. Keep in mind its not torn completely. I've heard a COMPLETELY torn plantar fascia is better because it will heal faster and causes less pain. I'm no doctor or anything, but that is what I've read.
I would play him in this game and see how everything works out and how he feels after the game. Depending on how he responded I may give him next week off against a weaker Dolphins team. The Giants game will be tough enough with Newman in the lineup.