Jimmie Gipson

South Alabama defensive end Jimmie Gipson is likely out for the 2016 season due to a knee injury. He missed all of 2015 with a torn Achilles tendon. (Chip English/South Alabama athletics)

Three-quarters of South Alabama's projected starting defensive line is likely out for the season, head coach Joey Jones said on Thursday.

AL.com had previously reported that defensive end Dewayne Alford will miss all of 2016 with an Achilles injury suffered in summer workouts. On Thursday, Jones revealed that nose tackle Tre Alford (no relation to Dewayne) and end Jimmie Gipson are both almost certainly also sidelined for the season with knee injuries.

Jones said Dewayne Alford might be eligible to return next season, but would have to apply for a medical redshirt through the NCAA. Tre Alford is a junior who has another year of eligibility.

Gipson would also have to apply for a sixth year, but having missed two full years, would almost certainly be granted a medical redshirt.

"(Dewayne Alford) may or may not come back next year -- that's to-be-seen," Jones said. "He would probably qualify for a sixth year.

"Tre Alford could come back late in the year, but not likely. Gipson ... there's a slight possibility he could play, but most likely out for the year."

It is the second straight season-ending injury for Gipson, who missed all of 2015 with a torn Achilles tendon. The 6-foot, 260-pound senior suffered his latest injury -- a torn ACL -- in practice, and was seen at Thursday morning's workout wearing a heavy brace on his left leg.

Tre Alford, who also suffered a torn ACL in summer workouts, was the Jaguars' most consistent interior defensive lineman last season. The junior started all 12 games, finishing with 37 tackles, 3.5 tackles for loss and two sacks.

Defensive line depth has been an issue for South Alabama dating back to last season, when Gipson, Dewayne Alford and various others all missed extended time due to injury. The Jaguars finished the 2016 season with just 11 sacks in 12 games, and were not especially stout stopping opposing running games.

"Just in case, I got cleared for my sixth year of eligibility," first-year defensive coordinator Kane Wommack said with a chuckle. "But I think we had some depth already when I got here. You never want to get hurt at any position, but we felt like coming in, if we could sustain some injuries at one position, it might be the defensive line."

The loss of Alford, Alford and Gipson leaves the starting defensive front wide-open in terms of competition. As of Thursday, sophomore Sean Grayer and senior Randy Allen appeared to be the favorites to start at the two defensive end spots.

Louisville graduate transfer Finesse Middleton is also expected to make an immediate impact as a pass-rushing end this season. Junior Jaylen Daniels had also been getting reps at end before being sidelined temporarily by a foot injury.

At nose tackle and defensive tackle, junior-college transfer Zach Befort and redshirt freshman Roy Albritton have been competing for first-team snaps. Sir Calvin Wallace, a graduate transfer from North Texas, will also be in the mix after starting for two seasons with the Mean Green.

Defensive end Rocel McWilliams, who joined the Jaguars over the summer from Missouri, must sit out this season due to NCAA transfer rules.

* In another roster note, Jones confirmed that true freshman defensive tackle Nick Fields had been advised to give up football due to a medical condition.

Fields told his hometown newspaper, The Dothan Eagle, last week that his problem was heart-related and first surfaced during summer conditioning work. Jones said the details related in that story were accurate.