Dolphins coach Brian Flores made it clear that Rosen, whom Miami acquired from the Arizona Cardinals on Friday night for a late-second-round pick and a 2020 fifth-round pick, won't be treated any differently than the rest of the players on the team.
"When Josh gets here, he's got to compete for any type of role that he has here. That's the case for everyone in the building," Flores said. "The guys who produce on the practice field and do all the things that help this team win -- those are the guys who will play."
Miami got great value in the trade for Rosen, who was the 10th pick in the 2018 draft, but he has a lot of work to do after posting the NFL's lowest passer rating (66.7) last season.
It's a fresh start for Rosen after the Cardinals drafted his replacement, Kyler Murray, first overall Thursday.
"He has a chip on his shoulder now," Dolphins general manager Chris Grier said of Rosen.
Value played a huge role in trading for Rosen, but the Dolphins also felt strongly about his character and defended him against criticism that recently surfaced. Some of that criticism included questions about Rosen's leadership skills and passion for football and whether he is well-liked by his teammates.
"Coaches unsolicited have called us that know him, that have worked with him, and say a lot of the stuff is B.S.," Grier said. "For us, we don't know him, because we don't have our hands on him, but we're going with the people we trust and know and the coaches and scouts in the building that have called, and people have said this is really a good kid that's smart. Maybe he has some other interests like following the stock market or something, but he's really smart, he loves football, he studies it and it's very important to him."
Added Flores: "You never get to really know a person until you sit with him every day, which we'll get that opportunity. We've done a lot of work on Josh. I think he's smart, he works hard, football is important to him and I think he has an opportunity to help this team win games."
The Dolphins did their homework on Rosen in last year's draft, as did Flores and new offensive coordinator Chad O'Shea during their time in New England. But they dug in deeper once the Cardinals began offering Rosen when this year's draft began. The negatives weren't what they seemed, according to Grier.
Rosen will get a chance to prove he can be the guy to solve the Dolphins' short-term and long-term quarterback problem. But the franchise quarterback label? It won't be given to him.
"You have to earn the right to get that kind of label," Flores said. "You have to do it in the meeting, on the practice field. To label a kid like that right off the bat, I feel like that's unfair in a lot of ways. You have to earn it."
Added Grier: "We didn't go out saying he has to be a franchise quarterback for us. For us, it was, he's a very talented young player, still has a lot of upside in the league and the terms for us, the value and taking on the contract and etc. -- for us, the value was tremendous that we couldn't afford to pass up."
Veteran journeyman Ryan Fitzpatrick has been penciled in as the starter since the Dolphins signed him to a two-year, $11 million deal last month and traded longtime starter Ryan Tannehill to Tennessee.
Miami is preparing for an open competition between Rosen and Fitzpatrick.
On Saturday, Rosen tweeted a video of him thanking the Cardinals, congratulating Murray -- even offering to rent him his apartment -- and announcing to Dolphins fans that he would arrive in South Florida ready to work Sunday morning.
The Dolphins have 10 picks in the 2020 draft, including an extra second- and fourth-round pick. Miami is also projected to have two midround compensatory picks. That load could put them in position to trade up for another quarterback in the 2020 draft if it doesn't work with Rosen.
But Rosen will get a good chance to prove his worth, and he apparently has coaches in Flores, O'Shea and quarterbacks coach Jim Caldwell who want to believe in him and maximize his potential.