New Dolphins head coach Brian Flores hasn't given a concrete timeline on when he'll name a starter, but on day one, it appeared the veteran took a lead over the sophomore.
Rosen's day included an interception in the end zone and a fumble on a handoff. Still, he was positive after practice.
"I thought I had a slow start but finished pretty strong," Rosen said. "I think it's about getting used to everything -- teammates, offense, situations and all of that. I think as long as tomorrow is better than today, I think we'll be good."
Fitzpatrick, on the other hand, had a solid day and was praised by his younger teammates.
"He's a leader for sure, and everybody looks up to him when he steps in the huddle," left tackle Laremy Tunsil said. "One thing (Fitzpatrick) says is 'Give me your eyes' and everybody looks and listens. He has that leadership and everybody respects that."
The Harvard grad took the majority, if not all, of the first team snaps while Rosen was relegated to the second unit, according to the Sun Sentinel.
Fitzpatrick had a number of touchdown passes and no turnovers reported.
"I'm just trying to be the best version of me that I can be. That really is it," Fitzpatrick said. "There are so many things that I've just continued to get better at in my game. Knowing who I am as a player and working on my deficiencies, communication is something I try to pride myself on."
So while it's only been one day, it seems like Fitzpatrick is leading the charge for the starting quarterback position.