GAINESVILLE, Fla. -

Florida might have to rely on its third-string quarterback for the second week in a row.
   
The Gators expect to start red-shirt freshman Skyler Mornhinweg in Saturday's home game against Georgia Southern, a team from the FCS. Mornhinweg made his debut last week when Tyler Murphy was out with an injury to his throwing shoulder.
   
Murphy,  who sprained his acromioclavicular joint, took over for original starter Jeff Driskel in Week 3. Murphy was unable to practice last week and is unsure when he'll return. Due to the uncertainty, Florida is working under the assumption that Mornhinweg will start.
   
"If we had to play today, yeah, that would be the plan moving forward," Gators coach Will Muschamp said Monday. "Tyler did some light throwing yesterday, felt comfortable. Not ready for him to practice today. We'll see how far he progresses.
   
"When you have the situation that he has, discomfort is a huge issue in the throwing shoulder. So if he says, 'I just don't feel comfortable throwing,' then he's not going to play."
   
Florida (4-6) relied heavily on its running game during Mornhinweg's debut at No. 11 South Carolina last week. The Gators rushed 41 times for 200 yards and asked Mornhinweg to drop back for just 13 passes. He completed 10 of 13 for 107 yards and had an interception in the final minutes.
   
Mornhinweg said he would prefer to throw more, but was fine with Florida's strategy.
   
"I'm confident in my abilities and I'm confident in the coaches' game plan," he said Monday. "Whatever they want to run out there, we'll execute it and I think we'll have a shot to win."
   
The Gators are optimistic that Murphy could return by Saturday or for next week's regular-season finale against No. 2 Florida State.
   
He struggled to throw last week due to the pain in his shoulder and was ruled out a day or two before the game. The injury affected his velocity and accuracy.
   
"It wasn't coming out pretty," he said.
   
Since replacing Driskel in Week 3, Murphy has completed 60.5 percent of his attempts and averaged 135.1 passing yards per game. He has six touchdown passes, three touchdown runs and five interceptions.
   
Florida needs to beat Georgia Southern (6-4) and Florida State to reach bowl eligibility. If that does not happen, the Gators will sit home during the post-season for the first time since 1990. Their 22-year bowl streak is the second-longest active run in the nation. They also are trying to avoid their first losing season since going 0-10-1 in 1979.