UCLA junior linebacker Myles Jack will miss the remainder of the 2015 season with a knee injury, according UCLA beat writer Joey Kaufman.

UCLA will face the Arizona Wildcats this Saturday, and Arizona's All-American linebacker Scooby Wright will try to practice this week after suffering a torn meniscus in the season opener, according to ESPN.

The UCLA Bruins are undefeated through three weeks of football, and will likely miss their dominant linebacker for the rest of the season. Jack is likely confident in his teammates, and likely wants them perform in his absence. He wrote "next man up," on his twitter feed on Tuesday.

That next man up will likely be Isaako Saviinaea, who actually had a big game last week with 14 total tackles and 1.5 sacks. It is unclear if Saviinaea will be moved to a different position and someone else will fill in, but he tends to hold the spot behind Jack.

Jack had six totals tackles last week, but came up big with a crucial interception. The Bruins won a tight game against the BYU Cougars 24-23. UCLA has a huge Pac-12 test coming of this weekend as they play the undefeated Wildcats.

Both teams are in college football's top-25, but one program could fall out of the rankings with a big loss.

The Wildcats have likely been anxiously waiting the return of their All-American linebacker. Wright injured his knee in the first game against UTSA, and was expected to miss three to four weeks.

"The biggest thing would be from the medical staff, is he 100 percent cleared and ready to go?" said head coach Rich Rodriquez, via ESPN. "It's not only from an injury standpoint, but is he back to where he can be effective and play at the level he's used to playing at? For any player, you want that to be the case before he comes back, if he can be the player he was before the injury."

Wright was an offense's nightmare last season, as he recorded a total of 164 tackles and 15 sacks. The Wildcats will likely be very happy if Wright is ready to play this weekend. UCLA is a man down, and Arizona may get their star linebacker back Saturday.

This will be an interesting game to watch as it could have a big impact on the outcome of who wins the Pac-12 South this season.