We continue our series looking at what several Pac-12 teams must do to catch reigning Pac-12 champion Stanford. Next up: UCLA.

How they make the Pac-12 championship game: It all starts with Josh Rosen. Going into his sophomore year, he's talented enough to develop into the best quarterback in the country and with that as a starting point, UCLA is in good hands. Although, as Cal proved with Jared Goff a year ago, a top-of-the-line quarterback can only take a team so far. The Bruins have a lot to replace on offense -- there is little experience on both the line and in the receiving corps and top running back Paul Perkins left early -- but several consecutive years of solid recruiting should prevent too much of a step back. They have high hopes for running back Soso Jamabo, who ran for 403 yards on 66 carries as a true freshman, and are expected to take on more of pro-style approach under new offensive coordinator Kennedy Polamalu. Looking around the Pac-12 South, there isn't really an overwhelming favorite. UCLA is certainly talented enough to come out of the division despite not being as experienced as it was a year ago.

What's holding them back: The lack of proven playmakers at receiver has to be at least mildly concerning. Losing Thomas Duarte early to the draft might have been the biggest blow because it wasn't necessarily expected. In fact, it was pretty surprising. Without him and Jordan Payton, Rosen is essentially starting over in a new offense while also developing trust with a new batch of receivers. If that doesn't end up as much of an issue, there's still the Stanford problem in general. If the goal here is to catch Stanford, there's not much in recent history that indicates the Bruins are up to it. Stanford has won the last eight meetings, which predates Jim Mora's tenure as head coach. Mora spoke about improving from a physical standpoint so it will be interesting to see if there is a noticeable difference in fall camp.

X factor: Defensive lineman Eddie Vanderdoes and cornerback Fabian Moreau are both expected to return after missing nearly the entire 2015 season due to injury. That's two all-conference caliber players injected back into a lineup that has to replace first-team defensive lineman Kenny Clark and -- to a lesser degree because he also missed most of last season -- linebacker Myles Jack. Vanderdoes may end up as the best defensive lineman in the Pac-12 next year.