San Francisco 49ers coach Kyle Shanahan said Monday that quarterback Jimmy Garoppolo sprained his throwing shoulder during the second quarter of Sunday’s playoff win against the Dallas Cowboys. Garoppolo is expected to be able to participate when the 49ers return to practice Tuesday, with Shanahan saying the starter’s shoulder is only “slightly” sprained. “He had to play through some pain and stuff, but he ended up checking out all right,” Shanahan said. “Just a slight shoulder sprain and he should be good for (Tuesday’s) practice.” Garoppolo was already dealing with a torn ligament in his right thumb, which caused him to miss one regular-season game, in which Trey Lance led San Francisco to a Week 17 win over the Houston Texans. Lance also started in place of Garoppolo in Week 5 — a loss to the Arizona Cardinals — while Garoppolo nursed a calf injury. Garoppolo, 30, completed 16 of …