"I am more motivated than I have ever been in my entire life," he also told ESPN after being selected, via the New York Post.
While Rosen fell behind all of them on draft day, many thought he deserved to be taken much higher:
The UCLA product also has plenty of confidence in himself, as he has shown throughout the predraft process.
"I'm the best QB in the draft," he said earlier this month, via Sam Alipour of ESPN The Magazine. "A lot of guys are flashier, but I think I'm the most efficient, monotonously consistent QB in this draft. [Aaron] Rodgers has some flair, but if you watch Tom Brady, Peyton Manning, Drew Brees, there's nothing that's explosive or Johnny Manziel-like. It's just quarterbacking."
Bleacher Report's Matt Miller listed him as the No. 3 quarterback in the class and the No. 8 player overall.
While Rosen might be upset about his position in the draft and the fact he was passed up for other quarterbacks, he at least enters a great situation in Arizona.
The more experienced players on the roster—Sam Bradford and Mike Glennon—won't necessarily block his path to the starting lineup once he is ready. There is also plenty of talent around him on the offense between Larry Fitzgerald and David Johnson.
The team went 8-8 last season despite mediocre play at quarterback between Carson Palmer and Blaine Gabbert, and Rosen could represent a major upgrade at the position.
If he gets onto the field, he will have to chance to prove a lot of doubters wrong.