PHILADELPHIA (973espn.com) - Put Tim Jernigan into the Carson Wentz category.

The Eagles' big defensive tackle underwent surgery to repair a herniated disc in his back last week and the timetable for his return has been set at four-to-six months, according to ESPN.

Like Wentz, who continues to rehab from the torn ACL and LCL he suffered in December of last season, the optimistic end of Jernigan's recovery would have him ready for Week 1 against Atlanta, albeit with no offseason or training camp.

The more cautious route, however, wouldn't have Jernigan available until eights weeks or so into the 2018 season.

An ominous sign to this, however, comes from Field Yates, who reports that the Eagles and Jernigan have reworked the four-year, $48 million extension from last November.

The final three years of Jernigan's deal are now all options years with no guaranteed money.

The contract tweak involves a March 16 deadline that guaranteed Jernigan's base salary of $11M in 2019. That is no longer definitive now, a nod to the uncertainty involving the Florida State product moving forward.

Jernigan, who starts next to Pro Bowl selection Fletcher Cox on the interior of Jim Schwartz's defense, played in 15 games last season, his first in Philadelphia after being acquired from the Baltimore Ravens.

He finished with 29 tackles and 2 1/2 sacks but his production and playing time dropped in the second half of the season as he struggled with an ankle issued.

Despite that, the Eagles signed Jernigan to the lucrative extension which included $26M of guaranteed money.

The Eagles will move forward in the offseason with Cox, veteran free-agent Haloti Ngata, as well as Destiny Vaeao and Elijah Qualls at the main pieces at defensive tackle. Others on the offseason roster include Aziz Shittu, Winston Craig, and undrafted rookie free agent Bruce Hector.

Despite turning 34 in January Ngata has proven to be an effective player, especially as a run-stopper, but is coming off a season in which he started the first five games for Detroit before suffering a torn biceps so he will also likely be limited or even held out of  OTAs.

The offseason will be a good opportunity for young players like Vaeao and Qualls to garner extra reps in an attempt to prove they are ready for a larger role come September.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen