After spending three years as Tom Brady's backup, Brian Hoyer gets a chance to start an NFL game.

SAN FRANCISCO -- When Brian Hoyer and Tom Brady talked on the phone Christmas Day, they didn't discuss how fast Hoyer should run through the Cardinals' tunnel during introductions or how wide he should smile when the cameras were in his face during warm ups.

The two former teammates caught up like old buddies. But instead of retelling stories about the good old days, they dissected the best approach to playing the San Francisco 49ers, who Brady and the New England Patriots played two weeks ago and who the Cardinals face Sunday.

Hoyer, who was Brady's back up in New England for three seasons, didn't ask for Brady's advice on starting his first NFL game. He learned enough from watching the three-time Super Bowl champion from a front-row seat.

"His work ethic and the way he approached every week was like his job was on the line," Hoyer said. "He didn't want anything to be unknown to him. He wanted to have total control of what the plays were and what the defense is doing. That's the one thing that amazes me the most. This guy has won three Super Bowls, how many MVPs, greatest player in the league and he's still so passionate about the game like he's a rookie.

"That's something that I really admired about him and tried to take with me. That's an attitude-type thing."

Hoyer now hopes all those years of preparing with Brady will translate into his own success, if for just one game.

Hoyer, who will be the Cardinals' fourth starting quarterback this season, earned the start in less than a half last Sunday against Chicago. He finished 11-for-19 passing for 105 yards and threw an interception on a pass intended for Larry Fitzgerald. Hoyer earned high marks from coach Ken Whisenhunt on his decision making, tempo and accuracy – all fundamentals he improved in New England.

Playing behind Brady gave Hoyer, who saw action in just 13 games in three years, plenty of time to sharpen his skills with former Patriots offensive coordinator and quarterbacks coach Bill O'Brien.

"You don't really need to coach Tom Brady, you need to give him plays," Hoyer said with a laugh. "So (O'Brien) had a lot of time to spend with me and work on fundamentals and things like that."

Brady obsessed over the fundamentals, so Hoyer did, too.

Whenever the defense or special teams were practicing, the two would work on footwork and passing drills.

"I think in my development, as far as mechanically, I came a long way just by working with him and just going through the drills he would do," Hoyer said.

But it was how quickly Hoyer learned the offense, at least enough to execute the game plan, that impressed Whisenhunt. Hoyer had just six practices to absorb the Cardinals' way and learn their lingo.

There are similarities between the Cardinals' and Patriots' offenses, Whisenhunt said, but Hoyer has said for the last two weeks that he breaks down the plays into his own personal jargon so he can better understand them.

"It will be interesting to see how he stacks up with a week to prepare," Whisenhunt said. "I know he's going against a tough defense. It will be a tough situation but it's a great time to evaluate him and see where he is."

Whisenhunt consulted with Jason Licht, the Cardinals director of player personnel, who overlapped with Hoyer in New England. It was Licht who called Hoyer on Dec. 10 with the news that the Cardinals claimed him off waivers. Whisenhunt also talked to his former colleagues in Pittsburgh, where Hoyer spent the three weeks prior to being claimed by the Cardinals.

But what also helped Hoyer land in Arizona was his time on the bench.

During the two seasons Whisenhunt played in Washington, he watched Joe Gibbs sit quarterbacks Mark Rypien and Stan Humphries for the first two years of their careers. Watching for that long helped them understand the speed and ferocity of the NFL, while teaching them how to prepare to play the game as a professional. Whisenhunt never forgot that.

"I think it's prepared (Hoyer) for this type of role where he's got to come in and learn something quickly and then act upon it," Whisenhunt said. "Having been in the league for the number of years he has, especially in that type of environment, there's no question that's helped prepare him for this."

Before they hung up and went about their Christmases, Brady did offer two pieces of advice to his former backup.

"He said, 'Good luck and have fun,' " Hoyer said.