INDIANAPOLIS – Pro prospects are as prepared as they've ever been for the NFL Scouting Combine, but that doesn't mean they're as prepared as ever for the NFL.

"We're not getting instant oatmeal anymore," general manager Dave Gettleman said. "We're drafting guys you have to change their diapers. It's crazy.

"Is it going to stop us from drafting a 20-year-old guy? No. It hasn't stopped us yet."

Gettleman, at the combine all week to evaluate prospects' readiness up and down the draft board, referenced legendary coach Bill Walsh's 1997 book "Finding the Winning Edge" as a still-valuable source on building an NFL team.

Walsh wrote about a "two-year rule," arguing that only after two years from a players' draft date do teams truly know what they have. That time frame may have shrunk for a while as players got better training in terms of their physical strength and their mental preparedness on the amateur level. But now, with spread offenses so rampant in college and so rare in the pros, the learning curve has steepened again in Gettleman's estimation.

"Back then the NFL was getting a much more finished product than we're getting now," Gettleman said. "Now, it's really a three-year rule. You've got to understand there are going to be growing pains. Nothing is easy."

That's one of the reasons, ironically, that Gettleman prefers to build teams through the draft. The Panthers find themselves in the best salary cap situation they've been in since Gettleman took over three-plus years ago, but he still prefers to pay Panthers "lifers" developed in the system while also adding players through the draft that can eventually become core players.

"We shopped at Tiffany's last year. TD, Greg, Luke and Cam - that cost more than a bag of doughnuts," Gettleman said, referencing offseason contract extensions for Thomas Davis, Greg Olsen, Luke Kuechly and Cam Newton. "You guys have seen my act for three years: I'm methodical, I'm intentional, and that's the approach I'm going to take whether we're 16 million over or 25 million under. I'm not going to change. It's working for us.

"It's about the draft. You draft well, you develop, and those are the guys you want because those are the guys in your culture. They understand what you're looking for, how to operate, what they need to do, what's expected. That's what you want, and then you want to fill in the other way."