Vikings quarterback Sam Bradford has been limited in practice all week with a knee injury.
ESPN's Adam Schefter reported Friday afternoon that Bradford underwent an MRI on his left knee earlier this week. Schefter's colleague, Chris Mortensen, said the MRI was negative after sources told him he was dealing with swelling, pain and discomfort.
It's the same knee that Bradford had two reconstructive ACL surgeries on over the last five years.
Head coach Mike Zimmer told reporters at a press conference that he's "not going to talk about it... who's had MRIs, who hasn't had MRIs, lot's of guys have MRIs."
The good news is that Zimmer said he expects Bradford will play Sunday at Pittsburgh.
It's not known how or when Bradford hurt his left knee.
If Bradford can't go, Minnesota will have to turn to Case Keenum to start. Keenum has a career passer rating of 78.4.
Linebacker Anthony Barr and cornerback Xavier Rhodes are also listed as questionable.