Both Illinois juniors told reporters Tuesday of their intentions.
Newton, ranked No. 23 on Mel Kiper's Big Board and No. 8 in a recent roundtable of ESPN draft experts, said he would not play in a bowl game if Illinois (5-6) lands one this winter. Randolph said he is undecided on a bowl game.
The Illini can become bowl-eligible by beating Northwestern on Saturday at Memorial Stadium.
"It's really important for me, trying to get my teammates one more game to play in," Newton told reporters. "I know a lot of people don't have careers after this, a lot of people won't go to the NFL, so just to have people playing one more game together as a unit, seeing my team play, that would be really big for me."
The 6-foot-2, 295-pound Newton, an AP second-team All-America selection in 2022 and a two-time All-Big Ten selection, has 47 tackles, including 5.5 sacks, as well as team highs in both quarterback hurries (8) and blocked kicks (3), and a forced fumble and fumble recovery.
The Florida native and team captain is a finalist for the Nagurski Trophy, awarded to the nation's top defensive player.
Randolph, also a captain who leads FBS defensive tackles in tackles per game (5.6), is also a two-time All-Big Ten selection. He appears at No. 9 on Kiper's list of top draft-eligible defensive ends for the 2024 draft. Randolph is tied for second on the team with four quarterback hurries.
"This is my final year here," Randolph told 247 Sports on Tuesday. "It's emotional. I've been here for a long time. I'm a senior. I didn't transfer. I've been here since Coach [Lovie] Smith. We've been through a lot of ups and downs and a lot of adversity. This place is my home, and it will forever hold a place in my heart."