The race for the Pac-12 South title has officially begun, and it starts with a face off of two of the biggest contenders.

No. 16 Arizona Wildcats will host No. 9 UCLA on Saturday at 5 p.m. The game will be broadcast on ABC, and ESPN’s College GameDay is visiting Arizona’s campus in preparation for the game.

In short, this game is huge.

Both teams come into the game at 3-0, having swept their non-conference opponents. Arizona’s most recent game was a 77-13 blowout of NAU. UCLA just edged No. 22 BYU 24-23.

“Obviously this is a big game, so everyone is excited,” said Arizona senior safety Anthony Lopez. “It doesn’t change what we are going to do on defense. Every week we come out here to work. It’s never more of a relaxed week, but there is more hype for this game.”

The biggest storylines stemming from this game are the injuries to key players. Arizona linebacker Scooby Wright III is listed as questionable with a knee injury he sustained in the Wildcats’ opener. Receivers Cayleb Jones (ankle) and Samajie Grant (knee) are also questionable.

Receivers Trey Griffey (foot), Tyrell Johnson (foot) and linebacker Haden Gregory (knee) will also be out of this game for Arizona.

UCLA suffered a huge blow Tuesday when its star linebacker, Myles Jack, suffered a torn meniscus, ending his season. Jack is arguably the Bruins’ most valuable player, who was a projected first-round pick in the NFL draft and a consistent nightmare for the Wildcats.

Jack’s injury comes after UCLA already lost defensive lineman Eddie Vanderdoes (knee) for the season earlier this year. Cornerback Fabien Moreau (foot) was also lost during the Bruins’ game against BYU.

Another big story coming into this game will be UCLA freshman quarterback Josh Rosen. Arizona will be Rosen’s first Pac-12 test.

After looking great in his first career start against Virginia, Rosen has come back down to Earth in his last two games. His performance against this Wildcat defense, and vice versa, could be the biggest factor in which team walks away with a victory.

“We need to play Arizona football. We need to play disciplined,” said senior safety Jamar Allah. “We need to play fast and start off fast, and we need to play physical and be focused.”

UCLA has beaten Arizona the last three times these teams have met.

Arizona’s up-tempo offense will need to continue to play mistake-free football when the Bruins come into town. Quarterback Anu Solomon has not thrown an interception yet this season, and running back Nick Wilson has been on a tear the past two games, rushing for 434 yards and five touchdowns.

ASU and USC already suffered early losses, which gives UCLA and Arizona a chance to make a statement in the race for the Pac-12 South title.

With College GameDay here and all eyes watching, this game between the Bruins and Wildcats will be a great conference start for both of these schools in what has already been a wild year for the Pac-12.