After watching Cam Newton's Week 1 performance, Stephania Bell feels that he can continue his strong and healthy play for a full season. (1:17)

CHARLOTTE, N.C. -- Had the Tampa Bay Buccaneers not reached an agreement with Tom Brady on March 17, they likely would have made a run at the quarterback they face Sunday, Teddy Bridgewater.

“He was very, very high on the radar,” Bucs coach Bruce Arians said this week.

Had Bridgewater gone to Tampa Bay, the Carolina Panthers might have kept Cam Newton and the 2015 NFL MVP wouldn’t be in New England, where he has replaced Brady.

That would have meant Sunday’s game between the Panthers (0-1) and Buccaneers (0-1) at Raymond James Stadium (1 p.m. ET, Fox) would’ve featured Newton vs. Bridgewater instead of Bridgewater vs. Brady.

Funny how things work out.

It remains to be seen how the four quarterbacks who switched teams as free agents this offseason -- Brady (Patriots to Bucs), Bridgewater (Saints to Panthers), Newton (Panthers to Patriots) and Philip Rivers (Chargers to Colts) -- will work out this season and beyond.

Newton was the biggest winner -- and the only winner on the scoreboard -- on opening weekend with a 21-11 victory over the Miami Dolphins. He looked healthy and ran like the quarterback who kept defensive coordinators up at night.

2020 Free Agent QBs: Week 1 How four NFL starting quarterbacks who changed teams and signed as free agents fared in Week 1: Player, team Comp-Att Yards TD INT QBR W-L Tom Brady, TB 23-36 239 2 2 34.5 L Teddy Bridgewater, CAR 22-34 270 1 0 75.5 L Cam Newton, NE 15-19 155 0 0 79.7 W Philip Rivers, IND 26-46 363 1 2 56.2 L ESPN

The others, according to Hall of Fame executive Bill Polian and ESPN analyst Dan Orlovsky, did exactly what they were expected to do -- minus a few costly mistakes by Brady and Rivers -- after an offseason with fewer workouts and no preseason games.

“My take was somewhat similar to baseball,” Polian said. “Why do you have exhibition games in baseball? Because of the pitchers, to get their timing down. The quarterbacks are the same way. They have to see every look.”

Polian said it takes about six games to fairly evaluate how successful these quarterbacks will be with their new teams. Orlovsky still “feels best about Tom Brady,” saying the Week 1 loss could have been the best thing to happen to him.

“To get absolutely kicked in the face, to have that quarterback go in there and make sure everyone knows that’s not who they’re going to be,” he said.

Let’s take a look at who they are after Week 1, with Newton at the head of the class:

Cam Newton

In 21-11 win over Dolphins

Passing: 15 of 19 (79.0%), 155 yards, 0 TDs, 0 INTs, 2 sacks

Rushing: 15 attempts, 75 yards, 2 TDs

Total QBR: 79.7 (7th in NFL)

ESPN analyst Marcus Spears strongly suggested on Get Up what Newton did in terms of running 15 times wasn’t a recipe for sustainable success, based on recent history with injuries.

Polian and Orlovsky agree, which puts the onus on Newton to be an efficient passer with a suspect group of receivers.

Newton completed 78.95% of his 19 pass attempts. Credit goes to offensive coordinator Josh McDaniels for putting Newton, with a career completion percentage below 60%, in good position with the playcalling.

Cam Newton resembled the quarterback who was at his best in 2015 with the Panthers, excelling in the zone-read game and making few mistakes. Maddie Meyer/Getty Images

All 19 of Newton’s attempts had a completion probability above 50%, according to ESPN Stats & Information research. That’s the most attempts with that probability by any quarterback in the past five seasons.

“I don’t know if I’ve seen Cam where he was that diligent through his progressions,” Orlovsky said.

Newton really didn’t make a bad decision. He looked fast, too. After missing the final 14 games last season with a Lisfranc foot fracture, he was clocked at 19 mph on two of his runs. That’s the fastest he's been clocked in a game in the past five seasons.

Newton ran the zone-read that was his bread and butter at Carolina 12 times for 55 yards, something the Patriots hadn’t run since Week 4 of the 2016 season.

“Everything looked like the old Cam, which makes me wonder if the Miami defensive staff watched any Carolina film,” Polian said.

Concerns moving forward?

Polian: “If you’re playing Cam based on what we saw Sunday, you have to say we’re not going to let him beat us with his feet.”

Orlovsky: “Most teams are going to try to calm that run game and force him to beat them in the air. Are those guys around him going to be good enough and how does his body hold up?”

Teddy Bridgewater threw for 270 yards and rushed for 26 yards in his Panthers debut. Grant Halverson/Getty Images

Teddy Bridgewater

In 34-30 loss to Raiders

Passing: 22 of 34 (64.7%), 270 yards, 1 TD, 0 INTs, 1 sack

Rushing: 4 attempts, 26 yards, 0 TDs

Total QBR: 75.5 (8th)

First-year Panthers coach Matt Rhule called Bridgewater’s debut “excellent.” Had it not been for a failed fourth-and-1 from the Las Vegas 43 with 1:23 remaining, he was confident Bridgewater would have “won the game.”

Polian agreed, saying that play should have been called for running back Christian McCaffrey instead of fullback Alex Armah.

“In the NFL, it’s players, not plays,” he said. “You want to give it to CMC there if you can."

That call aside, Orlovsky said it was obvious why the Panthers wanted Bridgewater to run Joe Brady’s fast-paced offense, which depends on pinpoint passing.

“Teddy made quick decisions, which is his calling card,” he said. “Teddy looked really comfortable with the empty package. He was aggressive with the football, too. This was not dinking and dunking.”

Bridgewater threw 15 passes 10-plus yards, tying for the second most in his career and his most since 2015. He completed eight of those for 177 yards, including a 75-yard touchdown pass.

That’s notable, because according to ESPN Stats & Information research, from 2014 to 2019, Bridgewater averaged the fourth-fewest air yards per attempt (6.8) in the NFL.

Concerns moving forward?

Polian: “None, really. It looked like Carolina got exactly what it wanted.”

Orlovsky: “They’re going to play better secondaries than the Raiders. Can Teddy feel real good about being aggressive with the football and not turn it over?”

Tom Brady

In 34-23 loss to Saints

Passing: 23 of 36 (63.9%), 239 yards, 2 TDs, 2 INTs, 3 sacks

Rushing: 3 attempts, 9 yards, 1 TD

Total QBR: 34.5 (27th)

Arians said he “thought we were ready for" everything New Orleans threw at Brady. That has to be somewhat concerning for a team that moved forward with the 43-year-old future Hall of Famer instead of the mistake-plagued Jameis Winston.

Brady’s two interceptions, including a pick-six, to go with two touchdown passes was reminiscent of last season, when Winston threw 30 interceptions.

Polian said there’s no comparison, as Winston (88 picks to 121 touchdowns) struggled with turnovers for five seasons and Brady has been a model of efficiency over 20 seasons (181 picks, 543 TDs and no season with more than 14).

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“The throw to [Mike] Evans was just a miscommunication on the route,” Polian said. “That’ll disappear.”

Both of Brady’s picks came within 2.5 seconds of the snap. He had only 3.5 interceptions last season on such throws, further evidence this isn’t something to worry about.

“Brady played well minus two plays,” Orlovsky said. “Throwing out from the left hash on the field. I can’t tell you the last time I saw Tom Brady do that.”

Concerns moving forward?

Polian: “He’s got to stay healthy.”

Orlovsky: “Does Bruce Arians truly do what’s best for Tom Brady and understand who his quarterback is?”

Philip Rivers

In 27-20 loss to Jaguars

Passing: 36 of 46 (78.3), 363 yards, 1 TD, 2 INTs, 0 sacks

Rushing: 1 attempt, 3 yards, 0 TDs

Total QBR: 56.2 (19th)

Rivers had a chance to lead the Colts to a game-tying score in the fourth quarter were it not for a dropped pass by T.Y. Hilton. His two interceptions thrown into tight windows cost the Colts points and likely the game.

He has an NFL-high 12 tight-window picks dating to last season, according to ESPN Stats & Information research, and that isn’t a recipe for success.

But overall, Polian and Orlovsky liked what they saw out of the 38-year-old Rivers, who spent his first 16 seasons with the Chargers.

“Philip obviously played really well, but kind of the same stuff that bit him last year bit him again Sunday with the late turnover,” Olovsky said.

That Rivers lost his Indy debut to a Jaguars team that dumped most of its stars and was an eight-point underdog made this one seem worse that it was.

Concerns moving forward?

Polian: “In Philip’s case, a terrific day was marred by two interceptions. He’s got to get used to different receivers, just like Brady.”

Orlovsky: “Late mistakes. That’s something where you’re going to have to hold your breath if you’re a Colts fan.”