If he's had a knee issue why was he playing down the stretch?
If the MRI does indeed reveal something, he could have gotten a jump on the clean up/rehab.
Because he could play just fine, probably a nagging thing.
Trust me, playing at his level and his position is extremely rough on the knees/hips. If it was anything serious, he wouldn't be able to perform/practice at all.
He performed, and was all-world for a majority of the season.
MRI should reveal whats going on, hopefully they can correct it and he should be in even better shape than he was all season.