Miami Dolphins running back Alexander Mattison underwent season-ending neck surgery on Sunday in Chicago after being tackled during a preseason game against the Bears. The 27-year-old expected to make a full recovery, and his teammates are confident that he will return in full form. With Mattison sidelined, veteran running backs Aaron Shampklin and Mike Boone have been signed to compete with rookie Ollie Gordon II for snaps behind starter De’Von Achane and second-year back Jaylen Wright.
Source: https://www.espn.com/nfl/story/_/id/45944474/sources-dolphins-mattison-season-ending-neck-surgery