Mayock released the third edition of his position-by-position draft prospect rankings Thursday, and the biggest head-turner came under center, where Manuel, the Florida State passer, shot up to No. 2 behind West Virginia's Geno Smith.
So what happened?
"The first three tapes I saw of Manuel prior to the Senior Bowl included the Florida game, and that's probably the worst game he ever played ... so I had a little bit of a bad taste in my mouth heading into the Senior Bowl," Mayock told NFL Network's "Path to the Draft" on Thursday. "I thought he had a solid Senior Bowl week, and coming out of the combine, I felt like there was a quiet buzz among some of the teams. Not just his workout. More importantly to me, they like the kid, they think he's smart and in the meeting rooms at night, he passed that test.
"This week, I went and put three more tapes on, so I've seen six of his games now. I like the Clemson tape, I thought he was really athletic and threw the ball well. ... You know I don't like this quarterback class, so if I'm going to make a mistake, I finally decided I'm going to make a mistake with a kid with size, arm talent and athletic ability, and I think that's what Manuel has."
Manuel is an ascending prospect. The 6-foot-5, 237-pounder gained heavy experience in the shotgun at Florida State and impressed coaches with his arm at the Senior Bowl. He's seen as one of the few quarterbacks in this draft physically equipped to operate out of the read-option. Manuel's mobility is a major plus, but he's widely seen as a raw talent. He's easily the most intriguing quarterback of the bunch, and that's the kind of player who often rises as April approaches.
At the same time, it has not been a banner week for Barkley. NFL Films guru Greg Cosell told NFL Network's "Path To The Draft" that Barkley is a fourth-round talent being paraded around as a first- or second-round pick on draft boards.
"No. 1, he has average arm strength by NFL standards," Cosell said. "No. 2, his feet are not particularly quick, he has slower feet. And three, he's a little shorter."
Manuel, meanwhile, has ideal NFL size, he can wing it and his mobility is a separating quality. This quarterback group remains hazy, but it makes sense Manuel is starting to climb in the eyes of those who obsessively watch tape.
Follow Marc Sessler on Twitter @MarcSesslerNFL.