USF QB Blake Barnett pre-snap in a game against Wisconsin on Aug. 30, 2019.

USF quarterback Blake Barnett will undergo season-ending surgery on a high-ankle sprain he suffered in a game against SMU on Sep. 28, sources told Bulls247 and Spectrum Bay News 9's Chris Torello on Thursday.

He entered the game at the start of the second half, while USF was down 34-0, and played the rest of the game after starting quarterback Jordan McCloud exited with a wrist contusion.

Barnett, 23, threw for 222 yards in that game and tossed three second half touchdowns. He did take four sacks in the game, due to a shaky offensive line that allowed the Mustangs ten sacks on the afternoon. He was helped off the field by a trainer following the 48-21 loss.

USF Head Coach Charlie Strong said last week that Barnett would not be available for the Bulls' game vs. BYU and would meet with doctors to re-evaluate the injury. It was the second consecutive game that the California native did not play, after not traveling to USF's game at UConn on Oct. 5.

It has been an up-and-down year for the senior quarterback, who started the year with the starting job and was replaced by McCloud in the second half of USF's game at Georgia Tech.

In four games this season, Barnett was 40-of-77 for 434 yards and four touchdowns. He threw two interceptions in the Bulls' season opener with Wisconsin, but none since.

Barnett originally was a member of the Alabama Crimson Tide after being named a consensus five-star recruit coming out of Santiago High (Corona, Calif.). He redshirted in 2015 before being named the Tide's starting quarterback in 2016. He was replaced by true freshman Jalen Hurts in Alabama's season-opener with USC.

He transferred in September 2016 and ended up at Arizona State, where he played in four games in 2017. He earned an undergraduate degree in liberal arts while in Tempe.

Barnett transferred to USF in 2018 and thrived at times as the Bulls raced out to a 7-0 start with him as the starter. He suffered an injury last November that kept him out of USF's games at Cincinnati and vs. UCF.

The injury didn't derail him from throwing for over 2,700 yards in 2018, along with tossing 12 touchdowns.

It's unknown at this time what Barnett's future will be, if he is eligible for a medical redshirt and will return to USF for a third season. As mentioned above, he used a redshirt in 2015, but not a medical redshirt. He has played four games, which is the maximum amount a collegiate athlete may play before being ruled ineligible for one.

McCloud will continue to be the starter and walk-on transfer Kirk Rygol will be the backup quarterback. Rygol's only pass in 2019 was a 33-yard touchdown completion in the waining seconds at UConn, two weeks ago.

This leaves the Bulls with only one scholarship quarterback (McCloud) healthy, and even he isn't completely healthy. Jah'Quez Evans has been used in a wildcat quarterback set, while Augie DeBiase and Kaden Frost are the other two walk-ons on the roster.