Most likely, Georgia Tech defensive linemen Christopher Crenshaw and Emmanuel Dieke will play strongside defensive end. What’s not determined is who will be the starter.

“Some good competition going there,” Tech defensive line coach Mike Pelton said.

Theirs is one of the handful of starting jobs up for grabs in the Yellow Jackets’ preseason camp. Both are seniors. Dieke is a returning starter who made 24 tackles in 14 games last season. Crenshaw, who played on the line and at linebacker in Tech’s previous 3-4 scheme, played 13 games as a backup in 2012.

“I’ve just got to play the run better and use my hands better, but it’s a work in progress,” Crenshaw said. “I’ve come a long way.”

At nose tackle, freshman Darius Commissiong, Jimmie Kitchen and Ben Keith are battling to be the backup to Adam Gotsis. At defensive tackle, where Euclid Cummings is the starter, Patrick Gamble, Francis Kallon and Justin Akins are in the mix. Gamble and Kallon are redshirt freshmen. Akins is a freshman. The four best interior players, regardless of position, will be in a rotation, Pelton said.

Pelton referred to Kallon, once a ballyhooed recruit from Central Gwinnett High, as “the big fella that everybody asks about.” Kallon’s size and athletic ability, as well as his path to Tech, has intrigued fans. After moving to Gwinnett County from London, he joined Central Gwinnett’s team in the spring of his junior season and shot up recruiting charts as a senior.

”Francis shows flashes, but it’s just too far in between right now, and you can expect that from a young guy,” Pelton said.

Pelton said he challenged Kallon to keep working hard and to retain the training he received during spring practice.

“I think sometimes he comes out, and he’s just not competitive,” Pelton said. “But I’m trying to just get him to compete every single play.”

Akins and Commissiong have impressed coaches and teammates.

“He’s really improving,” Crenshaw said of Commissiong. “You can tell he’s kind of powerful with his hands.”

Practice report: Tech practiced Tuesday morning and afternoon, its first of two two-a-day sessions during camp. The Jackets practiced in full pads in the morning before backing off in the second practice.

After Monday’s practice was deemed lethargic, “I thought the defense flew around (Tuesday morning),” coach Paul Johnson said. “They had a really good day. They got after the defense pretty good this morning.”

Gotsis nominated a tackle by safety Lynn Griffin as the play of the day from the first practice.

“They completed about a 10-yard pass, and Lynn just came in and hit him,” Gotsis said, clapping his hands for emphasis. “It was a nice, big hit. It’s always good to see.”

Griffin is a redshirt freshman who likely would have played last season as a freshman, but for an injury suffered in camp.

Thomas O’Reilly was the first-string center Tuesday morning, with Ray Beno out with a minor injury. Tech remains thin at the position, with Jay Finch likely out for a couple of more weeks because of shoulder surgery, Catlin Alford having left the team and now Beno, normally a tackle, sitting out. The second-team was centered by Niko Anderson, a freshman walk-on.

Said Johnson, tongue-in-cheek, “It was quite a show.”

Johnson’s appraisal of quarterbacks Vad Lee and Justin Thomas from the morning practice: “Not anything spectacular, not anything special.”

Bulking up: Gotsis added 10 or 12 pounds over the summer and is up to about 283 pounds, he said.

“I’ve got to chunk it on if I’m going to play inside,” he said.

Gotsis weighed 300 when he visited Tech on a recruiting trip in January 2012 and shed about 30 pounds between then and the end of the past school year. Like end Jeremiah Attaochu, Gotsis and other linemen trained hard over the summer with strength-and-conditioning coaches John Sisk and Matt Hickman to develop explosiveness out of a three-point stance.

“It’s definitely paying off, I can tell,” Gotsis said. “Euclid Cummings, he’s become so much quicker off the ball. It’s finally showing, all the hard work.”

Saturday scrimmage: Tech will scrimmage at Bobby Dodd Stadium on Saturday morning. The session will be open only to season-ticket holders. They can gain admission with photo identification and may bring guests. Ticket-office staffers also will be on hand for those interested in purchasing season tickets.

Typically, the scrimmages have been either closed or open to anyone, but the department is trying to add value to its season tickets. The scrimmage will begin at 9:30 a.m., with doors opening at 8:30 a.m.