GLENDALE, Ariz. — Twenty-four-year-old Jimmy Garoppolo — who has never played a meaningful snap in the NFL — will stand behind center and in front of the nation Sunday night when the New England Patriots play the Arizona Cardinals at University of Phoenix Stadium. It will be the highest-rated television program of the weekend.

Jimmy G is being asked to command the SS Belichick while Tom Brady, the greatest quarterback of his generation, begins serving a four-game suspension for his ambiguous role in the interminable, litigious, and abjectly stupid drama known as Deflategate.

Other than the superficial observation that Garoppolo is perhaps the only American athlete even more handsome than Tom Brady, we know virtually nothing about Jimmy G. He played his college ball at Eastern Illinois (never to be confused with Alabama or Southern Cal) and has not started a regular-season game in two seasons with New England. He has been the clipboard holder and mopup man for Brady, completing 20 of 31 passes in 11 games.

The goofy-yet-intriguing situation is without parallel in the long and fabled history of New England sports.

Carl Yastrzemski replaced the legendary Ted Williams in left field at Fenway Park in the spring of 1961. Throughout Yaz’s rookie season, one of the Boston newspapers ran a daily box comparing Yaz’s game to Ted’s corresponding game from his rookie season in 1939. “Just what I needed,’’ Yaz wrote in a biography. “I knew that as good as I got . . . I’d never be anything like him.’’

Yaz turned into a Hall of Famer and Triple Crown winner, but he was never Ted Williams.

Consider the plight of poor Hank Finkel, a gentle 7-footer from Dayton who replaced Bill Russell in the fall of 1969. Russell won 11 championships in 13 seasons with the Celtics, retiring abruptly after winning the final flag in 1969. Finkel, a part-time player with the Lakers and San Diego Rockets, was brought to Boston to play center. In Finkel’s debut season with the Green, the Celtics went 34-48 and finished out of the playoffs for the first time since 1949-50. Finkel is still bitter about getting blamed for the demise.

Jimmy G’s assignment is perhaps even tougher than Yaz’s or Finkel’s, because unlike Williams and Russell, Brady is coming back. Jimmy G is just keeping the throne warm until Tom the King returns against the Browns in Cleveland on Oct. 9. So this is not like 2001, when backup Brady was given a chance to win the QB job while Drew Bledsoe recovered from a ruptured spleen. This is not a legitimate audition. Bill Belichick has already told the world that Brady will return to the starting position when his suspension is over.

Through the decades, a handful of anonymous Red Sox pitchers were thrust into crucial moments and never heard from again. In 1948, manager Joe McCarthy chose mediocre righty Denny Galehouse to start a one-game playoff against the Indians at Fenway. Galehouse was routed, 8-3, and pitched only two more games in the majors. In 1967, manager Dick Williams started unknown rookie Gary Waslewski in Game 6 of the 1967 World Series and got away with it. Waslewski won only two games in ’67 and retired with a record of 11-26 after six seasons, but he pitched well into the sixth inning of his World Series start and the Sox won with a barrage of homers. Eight years later, Red Sox rookie reliever Jim Burton lost the seventh game of the World Series with one inning of relief and never won another game in the majors.

This is different. Garoppolo is replacing a legendary champion . . . but just for four games. And we have no sample to suggest how Jimmy G will do against the Cardinals, Dolphins, Texans, and Bills.

Backup quarterback Matt Cassel stepped in for Brady in 2008 when QB 12 got his knee blown up in the first game of the season. Belichick made things simple for Cassel and the Pats won 11 games, but they did not make the playoffs. Cassel parlayed his tryout into a big contract with the Chiefs, while Brady came back better than ever in 2009.

We suspect the Hoodie will dumb it down for Jimmy G. The quarterback looked shaky against the Panthers in his final preseason game, but he has yet to play with the full complement of New England’s offense weapons, and he won’t have Rob Gronkowski on Sunday. Look for a lot of short passes, tosses to the tight ends, and a smashmouth running game. Nothing high-risk. No stretching the field. Let your defense win the game. This will be Game Management 101.

Garoppolo is already a perfect Patriot, saying little and spouting the company line. He played everything cool during an awkward preseason in which Brady demonstrated unexpected insecurity and neediness. A conflicted Belichick was forced to integrate Jimmy G while satisfying Tom’s seemingly insatiable need to be The Man.

This resulted in the strange preseason deployment of Brady at a time when it was in the team’s best interest to prepare Garoppolo for the first four games. Garoppolo delivered the Belichick mantra throughout (“To be honest, everything has been straight Arizona’’) and even pretended not to notice the gigantic/hideous Brady banners looming over Gillette, until cracking for a moment Wednesday when he admitted that game day preparation is “a smoother operation’’ without Brady around.

Bingo. Some truth. That’ll get Jimmy called to the woodshed in Fort Foxborough.

So the Patriots’ quarterback situation at this hour is fascinating in addition to being unprecedented. The Patriots are going to play four games with a new guy behind center. Fair or unfair, it’s going to constitute a referendum on who’s the most important figure in Foxborough. Jimmy G’s success or failure will fuel the age-old argument regarding who gets credit for New England’s dominant run. Is it Tom or is it Bill?

Brady has been to six Super Bowls and won four of them. Belichick has been his coach for every game of his career. As noted by former Globie Ron Borges, in seven-plus seasons without Brady as his quarterback, Belichick is 52-62 and has missed the playoffs six times. The Hoodie is 1-1 in playoff games without Brady.

If the Patriots play poorly over these next four games, we can say it is all Brady. If Jimmy G gets the job done, then it’s the Belichick system that dominates the NFL. You can plug just about anybody in there.

It’s a lot of pressure and eyeballs on a kid from Illinois with an empty résumé and the full attention of Patriot Nation and NFL America.

Dan Shaughnessy is a Globe columnist. He can be reached at dshaughnessy@globe.com. Follow him on Twitter @dan_shaughnessy.