Dolphins quarterback Tua Tagovailoa exited during the first quarter of Sunday's game against the Buffalo Bills.
He was carted off after taking a hit on the team's second offensive drive.
Tagovailoa, the second-year product of Alabama, was just 1-of-4 prior to being injured. He was relieved by backup Jacoby Brissett, who threw an interception on his second possession.
The Bills built an early 7-0 lead thanks to a 46-yard touchdown scamper by Devin Singletary. Quarterback Josh Allen tacked on another seven points with a touchdown pass to Stefon Diggs on the following drive.
Tagovailoa and the Dolphins picked up a win over the Patriots in Week 1. They were 3.5-point underdogs for Sunday's contest, but moved to +18.5 and +900 moneyline on DraftKings' live lines after going down two scores.
The lefty signal-caller played in 10 games last season as a rookie, including nine starts. He went 6-3 as a starter and split time with Ryan Fitzpatrick.
The Dolphins have become formidable in the AFC East with head coach Brian Flores running the show. The franchise owned a preseason win total of 9.5 — tied with the Patriots and behind only the Bills in the division.
Flores is 16-17 over his career, but followed up a 5-11 opening campaign in Miami with a 10-6 clip last season.
Miami will head to Las Vegas in Week 3 to take on the Raiders, who upset the Baltimore Ravens in Week 1 on Monday Night Football.
