PEORIA, Ariz. (AP) — Left-hander Justus Sheffield and righty Justin Dunn are two pitchers the Seattle Mariners will be counting on in their starting rotation in the future. Both got a taste of the big leagues last season when they made their Mariners debuts. They figure to be a major part of Seattle’s rebuilding process this season as it enters its second year. Sheffield is in his second spring training with the Mariners. He says he learned last season that he has to get past bad outings and move forward.