ɪn hɪz fˈɜːst sˈiːzən, dʒˈænsən pˈɪtʃt æz ɐ fˈoːɹθ stˈɑːɹɾɚ ænd lˈɔŋ ɹᵻlˈiːvɚ, ænd hˈɛld ɐ ɹˈɛkɚd ʌv tˈuː θɹˈiː wɪð ɐ fˈaɪv.fˈɪfti sˈɛvən ˈiəɹə, bˌʌt ɛksˈɛld ɪn ɹᵻlˈiːf ɐpˈɪɹənsᵻz, ænd ˈɔːlsoʊ wɛnt tˈuː nˈaɪn wɪð ɐ hˈoʊm ɹˈʌn æz ɐ pˈɪntʃ hˈɪɾɚ.
In his first season, Janssen pitched as a fourth starter and long reliever, and held a record of 2–3 with a 5.57 ERA, but excelled in relief appearances, and also went 2–9 with a home run as a pinch hitter.