ATHENS — Georgia junior defensive lineman Trenton Thompson is leaving early for the NFL draft, according to a post on his Instagram account.

Thompson is the first Georgia underclassmen to declare for the draft.

An Albany native, Thompson was the nation’s top recruit in the 2015 class, per 247Sports. After a strong finish to his sophomore season – when he had three sacks in the Liberty Bowl – he struggled last spring with a medical issue, then a knee injury that caused him to miss two games this season. He finished his junior season with 38 tackles and zero sacks.

Thompson had three tackles in the national championship game, including an impressive play in which he made a hard hit near the sideline, after crossing the field. That’s the kind of play that Thompson is hoping attracts NFL scouts, combining his athleticism and size (6-foot-4 and 295 pounds).

“After long discussion with my family and coaches I have decided to enter the 2018 NFL Draft. I would like to thank my family, teammates, Coach Smart and the rest of the staff for all of their support the last 3 years. Coming to Athens was the best decision of my life and the memories and friendships I’ve made will last a lifetime. Playing in the NFL has been a lifelong dream of mine and I’m excited to see what the future holds. Even though I’m moving on to the next chapter, Georgia will always be home! I certainly want to thank the greatest fans in the country for their passion and support! Thank you Jolly Nation and Go Dawgs!!”

Thompson said after the Rose Bowl that he was “up in the air” about returning for his senior year. He clarified that another Instagram post in early December, which many took to mean he was coming back, was only meant to show pride in being a member of the Class of ’18.

This makes two members of this past season’s main defensive line rotation who are leaving: Starting nose tackle John Atkins was a fifth-year senior.

Junior Jonathan Ledbetter said before the Rose Bowl that he was planning to return for his senior season. Ledbetter had a strong national championship game, splitting a sack and a tackle-for-loss, and his return would be a big lift to the line in 2018.

Sophomore Tyler Clark also had a very strong finish to the season. Sophomores David Marshall and Julian Rochester are among those who will also take the sting off of Thompson’s loss. The team signed two defensive linemen last month: Five-star Brenton Cox, a defensive end, and Davonte Wyatt, an early enrollee who spent last year at a junior college, began practicing with the team in December. The team also has commitments from prospects Jordan Davis and Tramel Walthour.

Junior inside linebacker Roquan Smith, an almost certain first-round pick if he declares, has not announced anything as of Friday afternoon. Cornerback Deandre Baker, center Lamont Gaillard and receiver Terry Godwin were also mulling whether to return for their senior years.