Rubuta ci gaba ga wannan sakin layi - Kline ya yi aikin shekara a shekara ta 2004, a 2<unk>2 tare da 1.79 ERA. Ba ya mika wuya a ci gaba da yin aiki a gida a Busch Stadium, kuma ya rike batters na hagu zuwa.143 matsakaici. Ya kuma kasance wani ɓangare na Cardinals 'gudu zuwa gasar cin kofin duniya, inda suka fadi zuwa Boston Red Sox. Koyaya, bai sami damar jefawa a Wasannin Duniya ba bayan ya tsananta raunin jijiyar yatsa a cikin 2004 NLCS
a wasan da suka yi da Houston Astros.