Leonard Fournette will be without his “flashlight.”

LSU starting fullback JD Moore will miss the Tigers’ game against No. 8 Florida on Saturday night and could be out several more weeks with a strained knee ligament, two sources confirmed to The Advocate.

Moore, a former walk-on who received a scholarship this fall, injured a ligament in his left knee on a hard hit to the thigh during a one-handed catch against South Carolina last week. Moore did not return to the game, and coach Les Miles said afterward that the injury is not serious.

Moore, a sophomore, underwent an MRI on Monday. A return date is not unknown, but Moore won’t play when No. 6 LSU (5-0, 3-0 Southeastern) hosts the Gators (6-0, 4-0) on Saturday night in Tiger Stadium. The Tigers host Western Kentucky next week and then are off a week before the beginning of a brutal four-game stretch in November: at Alabama, vs. Arkansas, at Ole Miss, vs. Texas A&M.

“Man, he’s everybody’s flashlight,” Fournette said of Moore on Monday night. “He’s a tremendous player, even better person. I love being around him.”

Moore’s two immediate backups are unproven. They’re both true freshmen: Acadiana High’s Bry’Kiethon Mouton and Lakeshore’s David Ducre, the No. 1-ranked fullback in the nation in the 2015 class. Ducre enrolled early, but it’s Mouton who entered the game for Moore.

Ducre has not played this season, but Miles said Monday that he’d begin practicing as Mouton’s immediate backup.

“Young guys come to LSU to play big roles,” Fournette said Monday about the possibility of Moore missing the game. “Just like when (defensive back Jalen) Mills went down. Rickey (Jefferson) came in. Young guys have to step in.”

LSU’s game plan seemed to change without its star fullback. The Tigers aligned out of the shotgun or using a single-back set on more than half of their snaps through the first three quarters of the game against the Gamecocks (2-4, 0-4). Moore was hurt on LSU’s first drive of the game.

Playing without a fullback is something not new to this team. LSU lost fullback Connor Neighbors to graduation after last season, and the team played much of spring practice without using a fullback, offensive coordinator Cam Cameron said during preseason camp in August.

Moore developed late in the spring, over the summer and impressed during camp enough that Miles and Cameron heavily used him after the season opener. He made critical blocks in Fournette’s 200-plus yard performances against Auburn and Syracuse.

LSU meets Florida without its starting fullback for the second straight year. Neighbors did not travel to last season’s 30-27 win in Gainesville after an ankle injury. His backup, Melvin Jones, started and excelled in Fournette’s 140-yard outing at Florida.

Jones dropped out of school after the fall semester, thrusting the walk-on Moore and freshmen into big roles.

Fournette said Monday that Mouton is “going to be good. We’re just taking our time with him. JD is teaching him right now so is coach Frank (Wilson). We’re working with him each and every day.”

Follow Ross Dellenger on Twitter @DellengerAdv.