Lane Johnson has a MCL sprain and ankle sprain after MRI, per source. #Eagles RT is expected to play Sunday, however.— Jeff McLane (@Jeff_McLane) October 5, 2015
Johnson re-injured the MCL sprain he originally suffered late during the preseason. The ankle sprain would appear to be new. Despite being less than 100%, as McLane notes, Johnson plans to play. He's tough.
The Eagles really need Johnson in the lineup. When it comes to offensive line depth, the Eagles are thin right now. Starting left tackle Jason Peters has been dealing with an injury, though it's reportedly possible he returns to action this week. The Eagles placed starting right guard Andrew Gardner on injured reserve last week. Left guard Allen Barbre and center Jason Kelce aren't injured but they've been struggling.
Johnson has never missed a game due to injury before. He did sit out the first four games of the 2014 season due to suspension, however.