The non-contact injury occurred with the score tied at 40 and 10 minutes remaining in the third quarter. Matthews attempted to push off his left foot and drive to the hoop, but his leg gave way and he fell immediately to the court in evident pain. The 28-year-old shooting guard had to be helped to the locker room. He departed with four points and three assists in 18 minutes.
Matthews was photographed by The Oregonian sitting in a wheelchair after the game.
Originally acquired by Portland in 2010 as a defensive-minded backup for Brandon Roy, Matthews has blossomed into one of the league's best three-point shooters and held down the starting spot for most of his five-year tenure in the Rose City. His solid two-way contributions and ability to space the floor make him an excellent fit alongside All-Star point guard Damian Lillard, and he has served as one of Portland's emotional leaders for years. Entering Thursday, Matthews had appeared in every game for Portland over the last two seasons.
Matthews, who is averaging 16.1 points, 3.7 rebounds and 2.3 assists while shooting 39.1 percent from deep, will be an unrestricted free agent this summer, joining fellow starters LaMarcus Aldridge and Robin Lopez on the open market.
[daily_cut.NBA] Portland acquired shooting guard Arron Afflalo from Denver at the trade deadline. The eight-year veteran is the odds-on favorite to replace Matthews in Portland's starting lineup down the stretch.
Aldridge led the Blazers with 17 points and 12 rebounds. Nicolas Batum added 15 points, 12 rebounds and six assists.
Portland improved to 41-19. Dallas fell to 40-23.