Rosen has been in the spotlight since the moment he stepped on campus. Along with playing under the bright lights of Los Angeles, he was a 5-star prospect and the No. 11 overall player in the 2015 recruiting class, according to 247Sports' composite rankings.
The California native quickly took the reins of the UCLA offense. He completed 60 percent of his passes for 3,669 yards with 23 touchdowns and 11 interceptions in 13 games during a strong freshman season.
He was limited to six appearances in 2016 before suffering a shoulder injury that required surgery.
Rosen returned for the start of the 2017 campaign amid enduring NFL draft hype. He responded by tallying a 62.5 percent completion rate for 3,717 yards, 26 touchdowns and 10 picks.
The 20-year-old rising star posted those numbers after responding to questions about his love for the game during an interview with Bleacher Report's Matt Hayes.
"I don't know why [scouts] say things like that. Because I speak about things other than football? Come on. I want to play 15 years in the NFL. I want to be great. I want my team to be great, to win championships," Rosen said in August. "Tom Brady might be able to play three or four more years. That's ridiculous to even think about, and that's the bar. I'll play in the NFL as long as they'll have me, as long as I'm physically able to play. Is that love of the game?"
He added: "I don't love the game? Really? If I didn't love the game, I wouldn't be out here getting my ass kicked."
Ultimately, Rosen has flashed the potential to become a franchise quarterback at the NFL level, which is why he's been a constant presence in the discussion as to the top prospect in 2018. The 6'4", 218-pounder's lack of polish and consistency during his time with the Bruins show there's still room for improvement, though.
He will likely battle USC quarterback Sam Darnold as the best player available at the position throughout the draft process, and the winner of that debate could very well become the No. 1 overall pick. The other one shouldn't fall too far down the board given the need for QBs around the league.
Rosen may not come out and dominate as a rookie, especially if he lands with a rebuilding team without a star-studded supporting cast. But his tools are impressive, so he could take a big step in year two after a full season of development, similar to Jared Goff with the Los Angeles Rams.