No results on the MRI that I've seen so far... but just the fact that they sent him for that MRI so soon could be a bad sign.
If it was something they thought to be pretty minor, I'd think they'd give him a couple of days to see how it feels and then make a decision about MRI (or even DL). Fantasy Insider (EPSN) said they wouldn't be surprised if he was out a couple of weeks as a precaution.
Either way, as my precaution, I've picked up Aybar, as I'd expect him to take Figgins spot at the top of the lineup. Depending on Figgin's and Kendrick's status, I've got to believe he would stay in the lineup if Figgins got more than a day or two off.