All or nothing · This year, the annual rivalry game between the Trojans and the Bruins will decide the Pac-12 South champion. The winner will face Stanford in the Pac-12 championship game. – Maya Dondonyan | Daily TrojanIn a game that will determine the Pac-12 South champion, the Trojans will host the rival Bruins in the regular season finale. Both teams are 5-3 in conference while the Bruins have one more non-conference win than the Trojans.USC is coming into the matchup after a 48-28 loss to Oregon that snapped a four-game winning streak, while the No. 22 Bruins are coming off of a win against Utah in Salt Lake City.Both USC and UCLA have no shortage of talent on the roster, but have struggled with consistency all season. The game will likely come down to which quarterback is able to control the game. USC will be led by redshirt senior quarterback Cody Kessler, a three-year starter who has never beaten UCLA. The Bruins, on the other hand, will be led by true freshman Josh Rosen, who has never played USC.“We’ve got to have a mindset to come in Monday and be ready to go,” Kessler said. “We’re playing to win the South. Guys are going to be excited about that and it’s going to be a great week of preparation, but it definitely hurts with any loss.”Kessler has sophomore JuJu Smith-Schuster in his corner, though he has battled various injuries all season Smith-Schuster has 68 receptions this season for 1,217 yards and 10 touchdowns. Though he is not at 100 percent, he is listed as probable for Saturday’s game.“He’s a warrior. He’ll be fine,” Helton said. “He’s dealt with pain each and every week from Game 5 on. He’s one of those guys that shows up every week and gives it all he’s got.”USC has also greatly utilized the run game under Helton, with the duo of Ronald Jones II and Justin Davis combining for most of USC’s yards on the ground. The Trojans will likely call on the pair a lot on Saturday, as UCLA’s rush defense is ranked No. 84 in the nation.USC’s offense ranks 26th in the nation in points per game, while UCLA comes in at No. 41. On defense, UCLA has allowed 30 points in five of their last eight games. USC’s defense faltered last weekend as well, allowing a season-high 48 points against Oregon.Rosen will lead a UCLA offense that has been without star running back Myles Jack nearly all season after he suffered a season-ending injury. The true freshman has completed 60 percent of his passes this season, throwing for 3,124 yards and 19 touchdowns. He’ll face a USC defense coming off of its worst game all season, allowing nearly 50 points against Oregon.The annual rivalry game is always important, but this year it determines which team will face Stanford in the Pac-12 championship game and compete for a Rose Bowl berth.“Even though it’s for the championship game and we’ve got ourselves to this position, just focus on doing your job would be the biggest thing I could tell our guys,” Helton said.Kick off is set for 12:30 p.m. in the Coliseum.