ˌɔn fˈɛbɹuːˌɛɹi tˈuː, tˈuː θˈaʊzənd fˈɪftiːn, dʒˈænsən sˈaɪnd ɐ wˈʌnjˈɪɹ kˈɑːntɹækt wɪððə wˈɑːʃɪŋtən nˈæʃənəlz fɚðə tˈuː θˈaʊzənd fˈɪftiːn sˈiːzən, wɪð ɐ mjˈuːtʃuːəl ˈɑːpʃən fɚðə tˈuː θˈaʊzənd sˈɪkstiːn sˈiːzən.
On February 2, 2015, Janssen signed a one-year contract with the Washington Nationals for the 2015 season, with a mutual option for the 2016 season.