They had several months to assess not only Bradford's surgically repaired shoulder, but his character, before making the six-year deal worth at least $78 million.
Before vice president of football operations Kevin Demoff hit the negotiating table with Bradford's agents, the Rams had seen the quarterback in rookie minicamp and in OTAs. They took note of his interactions off the field, too.
"You can't get fixated on the guarantee," Demoff said in an interview with The Associated Press. "We know what we have, he's got talent."
The 2008 Heisman Trophy winner appears completely recovered from shoulder surgery that cost him most of his final season at Oklahoma. From all accounts, he's a player the downtrodden franchise can rebuild around, and doesn't appear to have let riches go to his head.
Bradford took more than his share of good-natured ribs after the first practice. The next day he was used as the return man on the punt team session, although coaches told him to stay well away from the ball.
"Sam had a rough night, just so you all know," Rams coach Steve Spagnuolo said. "Just the razzing. But he survived."
After Wednesday's practice, Spagnuolo complimented Bradford for his fiery nature.
"I do like the fact that when he makes a mistake he's not very happy, and he shows it," Spagnuolo said. "He's got some feisty to him. I think that's good in a quarterback."
So far, so good.
The team has also spent a lot of money on the men up front who will be protecting Bradford, even if those on the flanks are young. One tackle, Jason Smith, the second overall pick last year, missed half of his rookie season with a concussion. The other likely starting tackle is rookie Rodger Saffold, the first pick of the second round.
For now, Bradford is a backup behind veteran A.J. Feeley, learning the rookie ropes.
"The more we put in, the more I have to think," Bradford said. "Not slower, but you just start thinking a lot more with everything that's coming at you.
"The more I'm out there, the more comfortable I become."
Just having him around gives an offense that was the NFL's puniest last year during a 1-15 season a lot more promise. Bradford welcomes scrutiny from the coaching staff.
"If someone messes up, including myself, I expect to get jumped and I expect the coaches to come at me and tell me what I did wrong," Bradford said. "I hope everyone else feels that way, too."
Years from now, if things haven't worked out, it won't be for lack of effort.
"There's no deal at the top of the draft that protects you if the guy's a failure," Demoff said. "I trust our decision-making process, I trust the kid.
"It's a headline-making deal, I get that. I hope we get what we paid for."
Bradford's deal represents a jump of nearly 20 percent from the $41.7 million last year's No. 1 pick, Matthew Stafford, got from the Lions while working for the same agents.
The Rams prefer to focus on the total deal, worth $13 million a season, and getting the most out of Bradford.
"If we'd gotten a flat deal along with Stafford and the guy busts out after three years, do you think we're any happier?" Demoff said. "I hope he leads us to five Super Bowls and makes $86 million. I would be ecstatic.
"You want all these players to max out, you can't worry about guarantees."
The contract, which is 32 pages long, was briefly bounced back to the Rams by the NFL because of what Demoff said was a typographical error. Unlike the contract negotiations that weren't finalized until the night before the first full-squad workout, the revised deal was quickly approved the same day.
Demoff said it was something like buying a car. A pretty expensive car.
"You walk in and they offer you sticker. End of the month, they might start $5,000 below sticker. Wouldn't it be great if both sides said, 'Hey, let's start at the end?' But both sides always think, 'I can do a little better than this.'
"These deals, they all happen in a rhythm."