I really, really don't want to get into the goat conversation again. All I said is that Peyton is arguably the goat, and I made sure to point out I don't think that's the case.
While on that subject, let's go back to 1997.
Manning had already proven himself in three seasons in the SEC (with never once being able to win a big game against the Florida Gators, but I digress), and the Jete had the first overall pick in the draft. Parcells stuck to his script by acting as if he was a drill sergeant looking down on a recruit and acted as if wasn't sure who he wanted, completely misreading the adulation the Manning Corp was desperately seeking.
As a result Peyton returned to Tennessee for his senior year (where he would lose to Florida for a fourth time, which has to be an NCAA record for losses to a single other team by a QB). Parcells could have drafted either Orlando Pace or Darrell Russell (the consensus 1-2 picks, but he traded down instead. At #6 he could have drafted Walter Jones, but he drafted down again.
Instead he drafted James Farrior, who had a solid career .... with the Steelers.
tl;dr version: Peyton Manning decided he would rather play for
any other team than the Jete (and also forego the accompanying #1 draft pick contract money), over the possibility of a career ending injury while in college that would result in zero NFL money.