Dallas Cowboys offensive lineman Zack Martin is undergoing an MRI due to a back ailment.
Martin was not present at the team's walkthrough on Friday, and the reason became lear shortly thereafter. Martin is a crucial part of the Cowboys' offensive line, and him being healthy is a huge part of their plans this year.
According to Football Outsiders, the Cowboys ranked No. 8 in all of football in run blocking.
Source: Jon Machota