Jansen will be called upon as the closer Thursday against the Diamondbacks if necessary, Ken Gurnick of MLB.com reports.
Although Jansen has been hit hard since his return from the disabled list (seven runs through four outings), he'll be used during the ninth inning if needed. The 30-year-old sports a 3.09 ERA and 1.03 WHIP with 66 strikeouts across 58.1 innings this season despite his recent struggles.