SURPRISE, Ariz. — Nick Tepesch put an emphasis this off-season on getting more comfortable with his changeup. It’s a pitch that could become critical in his future success at the big-league level.Tepesch threw his changeup less than 5 percent of the time last season, relying primarily on his fastball and slider. He knows that needs to change.“I just didn’t utilize it as much as I should have,” Tepesch said. “So it was an emphasis I put on myself this off-season to get more comfortable with the grip and throw it more often. It’s felt good coming out and I am comfortable with it.”Tepesch’s newfound changeup has already caught the eye of manager Ron Washington, who pointed to it as one of the positives he’s seen early on in camp.