While some managers might try to temper expectations for a top prospect, Seattle's Lloyd McClendon is going in the opposite direction when it comes to Taijuan Walker. McClendon declared Friday that the team's top prospect is expected to be part of the Mariners' Opening Day roster. The 21-year-old right-hander made three late-season starts in the Major Leagues last summer, going 1-0 with a 3.60 ERA. Walker, who was named MLB.com's No. 6 prospect on Thursday, said those outing have given him something to build on. "It was a long season," he told MLB.com. "I definitely got tired. But I think those three starts in the big leagues definitely gave me a boost of energy. Now I know what to expect for the coming season. "I'm going to Spring Training to compete. Just prepare, go out there and have fun. ... I'm going out there with more confidence. I know what to expect from big league hitters, know what to expect in the clubhouse with media and stuff like that." Only two rotation spots are locked up -- by former Cy Young Award winner Felix Hernandez and 2013 Cy Young finalist Hisashi Iwakuma -- so Walker is in prime position to be one of McClendon's starting five. He was 9-10 with a 2.93 ERA and 160 strikeouts over 141 1/3 innings between Double-A Jackson and Triple-A Tacoma. The Louisiana native limited Minor League foes to a .217 batting average. Those numbers have created the assumption that Walker is ready for the big time. McClendon, who was hired by Seattle on Nov. 5, isn't immune to the expectations.