SCOTTSDALE, Ariz. — The Cactus League has barely begun, but the Rockies’ 2021 roster is almost set. The club is unlikely to add any big-league players, and unless it pulls off a spring surprise and trades star shortstop Trevor Story, Colorado will head into the April 1 opener against the Dodgers with the players they now have in camp. Injuries, or a breakout performance from a young player, such as infielder Colton Welker, could change things. The Rockies plan to go with five starters and eight relievers, leaving 13 position players on the 26-man roster.