Florida quarterback Austin Appleby (12) calls out the signals at the line of scrimmage during the second half of an NCAA college football game against North Texas in Gainesville, Fla., Saturday, Sept. 17, 2016. (AP Photo/Phelan M. Ebenhack)

By MARK LONG, AP Sports Writer

GAINESVILLE, Fla. (AP) — Florida quarterback Austin Appleby has starting experience, even in hostile environments.

More valuable for the fifth-year senior: His defense leads the nation in points (4.7), yards (129.7) and sacks (16). So the 19th-ranked Gators might not need Appleby to do too much at No. 14 Tennessee on Saturday.

Nonetheless, coach Jim McElwain insisted the game plan won't change without Luke Del Rio, who injured his left knee in a 32-0 victory against North Texas on Saturday night and likely won't play against the Volunteers.

"All our guys have good arms," McElwain said. "We'll stretch the field ... We're not going to change as far as throwing the ball down the field."

Appleby played in 17 games, with 11 starts, in four years at Purdue. He threw for 2,777 yards, with 19 touchdowns and 19 interceptions. He also ran for nine scores.

Although Appleby has done this before, including a start at Nebraska in 2014, there's really no telling how he will handle sold-out Neyland Stadium (102,455) on Saturday. It will be loud, obnoxious and arguably the most difficult place for anyone to make their first Southeastern Conference start.

"There's no experience like game experience," Appleby said. "I've played in the big stadiums before. It's not going to be new to me. It's just going to be another week of practice and get ready to play a game. We've got an unbelievable opportunity to go play in prime time in front of a great stadium, in front of a good team and we'll see where we're at. We're excited about it for sure."

A graduate transfer eligible to play right away, Appleby chose Florida (3-0, 1-0 SEC) because it provided the best opportunity to see the field. The Gators lost all three quarterbacks from last season, including Will Grier and Treon Harris, and had Del Rio making his third college stop in four years and two incoming freshmen.

Del Rio beat Appleby out for the starting job in August, although freshman Kyle Trask seems to have the most upside of the group.

"I want to be a part of something special," said Appleby, who completed 2 of 4 passes for 30 yards in relief of Del Rio on Saturday. "I don't think you ever want to be someone's caddie. You want to be the guy that's got the ball in their hand, and I'm excited about my opportunity.

"It breaks my heart that it had to come by an injury, and again I'm really hopeful that he'll be healthy and back with us as soon as possible, but I'm ready to roll. We've got a job to do."

Defensive lineman Joshua Wheeler hit Del Rio low late in the third quarter, drawing a personal-foul penalty. Trainers and coach Jim McElwain rushed to the field as Del Rio ripped off his helmet. Del Rio eventually got up and walked to the locker room without any assistance.

Clearly upset with the hit , McElwain started screaming at the North Texas sideline and had to be restrained by officials and then his players.

"Lucky to be able to play for a coach and teammates that care for me so much!" Del Rio posted on Instagram. "Thank you for your love and support Gator Nation as well. I'll be back as soon as I can. #BeatTennessee."

The injury overshadowed a dominant performance by Florida's defense, which allowed a school-record 53 yards on 50 plays. The previous mark was 59 yards allowed against Western Carolina in 2006.

Once McElwain settled down, he turned things over to Appleby — for the week, maybe longer.

"Nobody skips a beat," Appleby said. "A couple slaps on the butt, 'Here we go, let's do it men.' It doesn't matter who's in. It doesn't matter about any position. We've got such a culture here. We work so hard. We've got so much depth. We all have a job to do, and if we do our job, we'll be fine."