DAVIE, Fla. -- The Miami Dolphins made a big splash at quarterback Friday night, acquiring Josh Rosen in a trade with the Arizona Cardinals for a second-round selection (No. 62 overall) this year and a fifth-rounder in 2020.

The Cardinals used this year's pick on speedy UMass wide receiver Andy Isabella.

Arizona had wanted a first-round pick for Rosen, but the Cardinals' leverage diminished after they drafted Kyler Murray first overall Thursday and two other quarterback-needy teams selected passers in the opening round.

Rosen on Saturday thanked the Cardinals organization and its fans and congratulated them on getting "a helluva player" in Murray, while adding he couldn't be more excited to be a member of the Dolphins.

Cardinals general manager Steve Keim said Friday night that he would have been "fine" and "happy" keeping Rosen on the roster but trading him came down to getting enough value in return. Keim insisted he wasn't focused on that value being a second-round pick, instead weighing the difference between keeping Rosen on the roster against the players he could draft with or around No. 62.

"It was really about the opportunity," Keim said. "Certainly, all of us are big fans of Josh Rosen's, wish him well and think he's going to have a heck of a career in the NFL."

The Dolphins already had traded back in the second round from No. 48 to No. 62, collecting a 2020 second-round pick and a 2019 sixth-rounder while also giving up a 2019 fourth-round pick. That lesser-valued second-round pick made more sense for Miami to give up for Rosen.

Rosen, the No. 10 pick last year, immediately speeds up the Dolphins' rebuild. His acquisition also is a sign that Miami liked the value of Rosen better than selecting any quarterback in the first or second round outside of Murray and possibly Daniel Jones, who went sixth to the New York Giants.

A second-round pick is still a significant asset for the rebuilding Dolphins, so this indicates they will give Rosen a serious chance to prove he can be their franchise quarterback. It's also a strong move for Dolphins general manager Chris Grier to capitalize on Rosen's diminished value.

"It was an opportunity to add more competition and talent at a position," Grier said. "We've always talked about creating that competitive environment at every position. It was a grueling two days for both of us working through it."

The Dolphins now have 10 picks in the 2020 draft and are projected to have two more compensatory picks.

Miami was arguably the NFL's most quarterback-needy team after trading away longtime starter Ryan Tannehill and signing veteran journeyman Ryan Fitzpatrick as a stopgap last month.

Rosen becomes a leading candidate to start for the Dolphins in 2019, although Fitzpatrick likely will want to force an open competition. It'll be a chance for redemption for Rosen, who had an extremely rough rookie season in Arizona, completing 55 percent of his passes with 11 touchdowns, 14 interceptions and an NFL-low 66.7 passer rating in 13 starts (3-10 record). But he did so behind arguably the NFL's worst offensive line and on a team that fired its coaching staff after one season.

"He was always a guy that's had a ton of talent," Grier said of the former UCLA standout. "He's a guy that everyone knows has arm talent. What everybody always liked about him is how cerebral he was as well. It's a young, talented guy at a premium position in this league."

Leadership has been a key intangible for new Dolphins coach Brian Flores, and Rosen will have to show his growth in that department. Rosen reportedly handled the uncertainty of the past few months well.

Flores and offensive coordinator Chad O'Shea were "very involved" in the trade, Grier said, and added that it will be up to Flores if Rosen will start over Fitzpatrick.

"Ryan Fitzpatrick has been great," Grier said. "He's got a personality, as you guys know he's a character, great leader. So the two of them will be good."

Arizona already paid Rosen's signing bonus, so he is set to make just $6.24 million over the next three seasons -- a bargain for a starting quarterback.

The Dolphins had a shot at Rosen in the 2018 draft before the Cardinals traded up one spot ahead of them and landed him with the No. 10 selection. Sources told ESPN that Miami was primarily interested in Baker Mayfield and Josh Allen. So what's the difference now? A lower value for Rosen and a new coaching staff might have the Dolphins believing they can get more out of the former top-10 pick.

"I wouldn't say we didn't like Rosen [a year ago]," Grier said. "It's a different coaching staff for what they're looking for at the position. At that point, we were talking about top-10 pick and he just wasn't in those five or six guys we were comfortable taking at Pick 11."

Rosen's brief tenure in Arizona was turbulent.

The Cardinals traded up from 15th to 10th in the first round to take him. That night, he declared there were nine mistakes taken ahead of him. He toned down his rhetoric the next day by saying there were only three mistakes taken ahead of him -- the three other quarterbacks picked: Mayfield, Sam Darnold and Allen.

However, Rosen's rookie season didn't back up his braggadocio after he took over for a struggling Sam Bradford late in Week 3.

Keim said he never actively shopped Rosen but he had a "number" of conversations with teams about the QB starting around the time of the NFL scouting combine in February. Keim had not talked to Rosen before his news conference, which started late in the third round Friday night.

"The bottom line is a team has to make a hard offer, and I always leave that door open because it's my job whether I'm actively shopping somebody or not to let somebody know, 'Make me an offer,'" Keim said.

But as the Cardinals continued to scout and evaluate Murray, they felt they had a clear-cut decision in front of them.

Keim wouldn't say that Rosen didn't work out in Arizona.

"I don't know that it wasn't that he didn't work out," the GM said. "I would say, obviously, he was put in a tough situation last year. But I think, really, when you come down to the bottom line, is we had an opportunity to find a dynamic player that we think can be special."

Now Rosen gets a fresh start, and Miami has its quarterback, at least for now. The path is clear for Murray and Cardinals coach Kliff Kingsbury to work their magic together without a distraction. But these teams' paths will be intertwined for years to come.