Those who have labeled Manziel as a top-10 pick felt vindicated as the Lone Star State native displayed impressive accuracy, better-than-advertised arm strength, and a substantial improvement in mechanics thanks in large part to his recent work with quarterback whisperer George Whitfield.
Manziel also affirmed the theory that he embraces the big stage, basking in an environment which included dozens of reporters, as well as personnel from 30 of the 32 NFL teams, and former President George H.W. Bush, along with his wife Barbara and their dog.
The athletic signal caller even won over some detractors by wearing a helmet and shoulder pads during the session while taking numerous snaps from under center and avoiding the comfort of the pistol and shotgun formations.
Those who question whether Manziel belongs anywhere near the first round of the draft, however, were hardly swayed by the handful of pro-Manziel reporters on hand who acted like teenage girls attending a boy band concert. To the critics, things should go well when everything is scripted, although most were forced to admit Manziel's ability to avoid a broom was top notch.
Count new Minnesota Vikings coach Mike Zimmer, a classic old-school NFL guy, among those who were unimpressed despite the fact that his new team holds the No. 8 overall pick and is in desperate need of a long-term answer at the game's most important position.
Zimmer called Manziel's pro day "choreographed" and said it placed too much emphasis on style instead of substance.
"The huddles and the different things and the music, it was a sideshow," the gruff Zimmer said.
The style over substance charge is one that has haunted Manziel since the day he arrived in College Station.
"I'm from a small town of Kerrville, Texas, 20,000 people," Manziel said. "(I) get lost in the kind of the people who make me out to be a big Hollywood guy. I'm really just still a small-town kid."
Other coaches, like Tampa Bay's Lovie Smith and Jacksonville's Gus Bradley, hopped on the "Johnny Bus" at Manziel's pro day and enjoyed the ride.
"Pretty much like I thought he would do. He's been a great player for a long time," Smith said. "The guy's a football player. He can do it all. Most guys come out in T-shirts and you don't play in T-shirts, so coming out made a statement throwing it in pads. Accurate. Great mobility. Then, he has great video. There are a lot of things to like about him."
Perhaps more importantly for Manziel, Bradley was equally complimentary.
"The atmosphere and everything that was involved and then to come out and perform like he did, that was great," the Jags' coach said. "I think that's no different than how he's performed all year, right? Perform under pressure. Felt like more of a pressurized environment with a lot of eyes watching him and he did a great job."
Bradley's take is most important because Jacksonville has the No. 3 overall pick and also is looking for an answer at QB position while veteran Chad Henne serves as the bridge. In fact, the Jags, along with Houston, which has the No. 1 overall selection, Cleveland (No. 4) and Oakland (No. 5), will likely determine Manziel's fate at Radio City Music Hall.
If none of those aforementioned teams bite early, Manziel could be in for a lengthy fall to late-first-round or early-second-round status.
"It would be awesome," Manziel said when asked about being drafted early. "When you put in a ton of hard work, it's a huge testament to how coaches and teammates all the way from when I first started playing this game. It's been a long process, not just a short road to get here."
Manziel's strengths and weaknesses have been debated ad nauseam since he burst on the national scene as a freshman. At just under 6-foot he certainly doesn't look like a prototypical NFL QB, but his overall athletic ability and movement skills make him a big play waiting to happen outside the pocket.
"I play with a lot of heart, play with a lot of passion," Manziel said when describing his game. "I feel like I play like I'm 10-feet tall. A measurement to me is just a number."
Plenty of observers question whether Manziel can stay healthy at the NFL level if he plays with the same style he did at A&M and many more have lobbed salvos at his leadership skills, pointing to his off-the-field issues in college.
"I have an opportunity now moving into a professional phase. This is life now, this is a job for me, taking it very seriously and I'm really excited about the future," Manziel said before redirecting things to his on-field maturation.
"I think you look at on-the-field stuff, from freshman year until what I was this year, I tried to really hone in on some things this year, get better in the pocket and continue to develop as a passer."
To the few "undecided voters" on Manziel, the most important aspect coming out of his pro day was that willingness to work on his perceived deficiencies whether it be his somewhat shaky mechanics and foot work or his ability to grip it and rip it from the pocket.
"I'm looking forward to shoring up all the people that are saying that I'm just an improviser," Manziel said. "(I) feel like I worked extremely hard this year to all-around hone in on my game, getting better as a pocket passer and as a quarterback in general."
For now, though "Johnny Football" has morphed into "Johnny Boom or Bust." Some scouts love him and some think he's destined to fail.
"Whatever happens is really meant to be," Manziel said.
The Sports Network's top quarterbacks in the 2014 NFL Draft:
1. - Teddy Bridgewater, Louisville
2. - Derek Carr, Fresno State
3. - Blake Bortles, Central Florida
4. - Johnny Manziel, Texas A&M
5. - A.J. McCarron, Alabama
6. - Jimmy Garoppolo, Eastern Illinois
7. - Aaron Murray, Georgia
8. - David Fales, San Jose State
9. - Zach Mettenberger, LSU
10. - Logan Thomas, Virginia Tech
The Sports Network's Stock Watch:
Sleepers - Fales; Tom Savage, Pittsburgh
Small School Standouts - Garoppolo; Jeff Mathews, Cornell
Risk/Reward - Manziel; Tajh Boyd, Clemson