According to Jeff McLane of the Philadelphia Inquirer, Philadelphia Eagles All-Pro starting left guard Evan Mathis has suffered a MCL sprain.

After an MRI, #Eagles G Evan Mathis' knee injury doesn't appear season ending, but he's going for a second opinion on Weds. — Jeff McLane (@Jeff_McLane) September 8, 2014

Evan Mathis' knee injury is being labeled an MCL sprain. It's worse than Grade 1, likely 3. Not season-ending. But will have second opinion. — Jeff McLane (@Jeff_McLane) September 8, 2014

Evan Mathis will be out for an extended period if diagnosis holds up, back for stretch run. #Eagles could possibly use short-term IR. — Jeff McLane (@Jeff_McLane) September 8, 2014

As McLane notes twice, Mathis will go for a second opinion later this week.

The good news is that it seems Mathis did not suffer a season-ending injury. Considering the way Mathis went down in pain and had to be carted off the field in the Eagles' 34-17 win over the Jaguars, this is an encouraging sign. It also confirms a report from Sunday afternoon which indicated Mathis suffered an MCL injury and not an ACL injury.

The bad news here is that Mathis will likely miss some significant playing time. The absence of Mathis especially hurts the Eagles due to the four-game suspension status of Lane Johnson and the injury status of Allen Barbre. Barbre reportedly suffered a high-ankle sprain and is expected to miss several weeks.

It goes without saying that Philadelphia's offensive line depth will be tested in the absence of Mathis and Barbre. Three starters remain in place: Jason Peters, Jason Kelce, and Todd Herremans. Behind them, the Eagles' backups such as David Molk, Andrew Gardner, and Dennis Kelly will need to step up. Top backup Matt Tobin is still nursing an ankle injury and could be a few weeks away from returning. The suspended Johnson isn't able to return to the team until September 29th.

When healthy, the Eagles have one of the best offensive lines in the NFL. It remains to be seen how the team will fare with their backup replacements.