CLEMSON -- Sentiment about the severity of Clemson defensive tackle Rashaad Jackson's knee injury swung Sunday when he hobbled to the team photo with crutches and a cumbersome brace.
Those fears later materialized with word Monday that Jackson tore a quadriceps tendon in his right leg. He suffered the injury while making a move during Saturday's scrimmage.
Jackson, a returning senior starter from Union, will be out until at least midseason, according to a school release -- if not longer.
"Any time you lose a guy like that, you're talking about a guy who's NFL material," defensive line coach Chris Rumph said. "You've got to fill in with some roles. But we have confidence with those guys. They just have to grow up a year early."
Those guys would be junior Jamie Cumbie and sophomore Jarvis Jenkins.
Cumbie (6-foot-7, 275 pounds) arrived at Clemson as a highly touted defensive end prospect but shifted to the interior during the second half of last season.
Coaches had quietly played Cumbie ahead of Jackson with the first-teamers in practices late last week, and coach Tommy Bowden praised Cumbie on consecutive days for learning how to improve his leverage in light of his height.
"I've gotten some experience, I'm as strong as I've ever been and I'm confident," Cumbie said. "It's like high school, you start at the bottom and work your way up. It's my junior year, so I don't have any excuses."
Cumbie sits atop the depth chart, but the wild card is Jenkins, a 6-3, 303-pounder from nearby Central who arguably boasts the most potential among those at the tackle position.
Jenkins has reshaped his body upon losing 23 pounds since the winter, and defensive coordinator Vic Koenning said he recently approached Rumph about working Jenkins with the starting unit.
"It's a little easier for us to sustain now than it was a couple years ago, for sure," Koenning said. "That's why you recruit."
If necessary, the Tigers would also consider moving second-string nose guard Miguel Chavis to tackle. Senior Jock McKissic and junior Antwon Murchison round out the depth chart.
Rumph said Jackson's injury and subsequent shuffling would not effect the status of freshman nose Brandon Thompson, who appears likely to redshirt.
"Jamie's slippery and can do some things pass-rushing wise," Rumph said. "Jarvis is a big bull in there and can be a plugger. We have to make sure both guys are balanced so we don't have to be limited on our play-calling."
At a minimum, Jackson (6-2, 290) is slated to miss the Aug. 30 opener against Alabama as well as ACC games against N.C. State and Maryland.
Jackson is scheduled to undergo surgery today, and the expected timetable for recovery is 10 weeks, meaning his return might not occur by key games Oct. 9 at Wake Forest or Oct. 18 against Georgia Tech.
Koenning raised the possibility that Clemson could even seek a medical redshirt for Jackson and pursue a rare sixth year of eligibility from the NCAA.
Jackson suffered a broken foot his first year and redshirted.
He declined an interview request Monday.
n TAYLOR STILL ABSENT: Senior running back Rendrick Taylor did not return to practice Monday, as Bowden had suggested he would the day before.
Taylor, who has been excused since Thursday, could be back today, Bowden said, although there is no rush with the likelihood Taylor will redshirt this season.
Bowden has said Taylor's absences were related to family issues Taylor anticipated before August practice began. Attempts to reach Taylor were unsuccessful.