ESPN's Adam Schefter broke the news, while Ian Rapoport of the NFL Network provided the full trade breakdown:
Seth Walder of ESPN gave some perspective on how much value the first-rounder could net the Dolphins:
ESPN's Chris Mortensen reported on Sept. 13 the Dolphins granted Fitzpatrick permission to seek a trade because he was unhappy being asked to play multiple positions.
Miami defensive coordinator Brian Flores told reporters during the offseason he planned to use Fitzpatrick at linebacker, cornerback and safety.
Mortensen added Fitzpatrick's agent, Joel Segal, was in contact with multiple teams, but the Dolphins weren't actively shopping the 22-year-old.
Miami selected Fitzpatrick with the 11th overall pick in the 2018 NFL draft. The former Alabama star appeared in all 16 games as a rookie and tied for second on the team with nine passes defensed.
Things started rough for Fitzpatrick in 2019 when he allowed 117 yards and three touchdowns on six receptions in the Dolphins' 59-10 loss to the Baltimore Ravens in Week 1, per Pro Football Focus' Ryan Smith.
Despite those struggles, Pro Football Focus' Austin Gayle noted in May the Dolphins weren't doing Fitzpatrick any favors because his best position is as a slot cornerback:
"He earned an impressive 79.3 overall grade and a 76.7 coverage grade across his 379 snaps in the slot this past season. Among the 34 defensive players with 200 or more coverage snaps in the slot last season, he ranked first in completion percentage allowed (51.3%), first in passer rating allowed (53.4) and tied for ninth in coverage grade (76.7).
"Only five other NFL defensive backs with 200 or more slot coverage snaps as rookies earned higher coverage grades in the slot as first-year players: Casey Hayward Jr. (90.8), Desmond King II (89.3), Leon Hall (81.5), Tyrann Mathieu (80.1) and Antoine Cason (79.4)."
Fitzpatrick was one of Miami's most valuable assets because of his youth and contract status. He's signed through 2021 and will make $4.7 million in the next two seasons combined. The deal also includes a team option for 2022 since he was a first-round draft pick.
Given the value of cornerbacks right now, Fitzpatrick will fit in with any defense. Slot receivers have become a crucial part of NFL offenses, especially with players like Larry Fitzgerald and Adam Thielen lining up there.
The Dolphins are in the first phase of a long-term rebuilding effort. Trading Fitzpatrick does make their defense worse, but their main focus at this point is adding long-term draft assets.
Being able to add a young defensive back with a proven track record of success and multiple years of control remaining on his contract made the deal for Fitzpatrick a no-brainer for the Steelers.
Since they gave up a first-round pick, the Steelers are obviously looking beyond just 2019 with this move.