Miami Dolphins running back Alexander Mattison will miss the entire 2025 NFL season after undergoing surgery on a neck injury sustained in Sunday’s 24-24 preseason opener against the Chicago Bears at Soldier Field. The 26-year-old was tackled on a 21-yard reception early in the fourth quarter, transported from the field by ambulance and operated on later that day in a Chicago hospital. Mattison, who signed a one-year deal with Miami in March, had scored the Dolphins’ first touchdown earlier in the game and had been among the club’s standout performers in training camp. He entered camp as the No. 3 option behind starter De’Von Achane and second-year back Jaylen Wright. With Mattison sidelined, the Dolphins are evaluating backfield reinforcements and have scheduled a workout for free-agent veteran Jamaal Williams, according to local media reports. Williams, 30, led the NFL with 17 rushing touchdowns for Detroit in 2022 before spending last season with New Orleans. A third-round pick of the Minnesota Vikings in 2019, Mattison has accumulated 2,790 rushing yards and 15 touchdowns over six seasons, including stints with the Vikings and Las Vegas Raiders. The team has not yet provided a timetable for his recovery beyond confirming he will be out for the year.