Tigers manager Brad Ausmus confirmed that Nathan is the team's closer to begin the spring, the Detroit News reports.In addition to confirming Nathan as the closer, Ausmus stated that Joakim Soria is the team's eighth-inning setup man. While those roles are exactly what has been planned throughout the offseason, it's clear that the leash for Nathan is shorter than it has been in the past, as Soria and Bruce Rondon could become options to step into the ninth-inning role if Nathan's 2014 struggles persist.