Of all the rookies who contributed to the Cardinals’ arms race for a National League pennant and World Series appearance, arguably the most dominant of them all wasn’t a starter. He just wants to be one. Trevor Rosenthal, who inherited the closer role on the eve of the postseason, pitched a scoreless eighth inning Wednesday night at Fenway Park to complete his October without allowing a run. Rosenthal struck out nine of the 16 batters he faced in the World Series and 18 of the 40 batters he faced this postseason. The righty blistered opponents with a fastball that averaged better than 98 mph and routinely touched 100 mph. He was everything the Cardinals wanted in the ninth inning. He’ll come to spring training with a chance to be want he wants. Rosenthal said earlier this season that he had hoped his first big-league win would come as a starter, and he’s been consistent with his wish to start all season. He, Carlos Martinez, Tyler Lyons, Seth Maness and lefty Kevin Siegrist all spent time in their minor-league careers as starters, and several of them could project as starters in the big-league rotation. “We plan on giving these guys a lot of opportunities,” manager Mike Matheny said. “Some of them really want to start. They’ve proven that they can start. We’ll spend time this winter evaluating where we are as a club, where we think that they can be individually, and how they can help us moving forward. We’re not afraid to stretch them out like we did Trevor Rosenthal this past spring. We told him to be ready to start. We’ll make adjustments as we (see) what’s best for our team.” Rosenthal has struck out a batter in 12 consecutive postseason appearances. Overall this October he allowed four hits and seven base runners in 11 2/3 innings while holding opponents to a .108 batting average. Although he relied mostly on his fastball — striking out the side in one World Series appearance on 11 consecutive fastballs — Rosenthal has the three-pitch mix that teams seek in a starter. He came to this year’s spring training with the chance to joust with Joe Kelly and Shelby Miller for the opening in the Cardinals’ five-man rotation. Rosenthal was removed from the contest when the Cardinals’ acknowledged his value as a flamethrower out of the bullpen. Martinez will come to spring training in a similar spot. A starter throughout his career in the minors, Martinez had a Rosenthal-like rise late this season to the eighth-inning role, where he pitched mostly in October. Siegrist and Maness had specialized relief roles.