Mezue ahịrịokwu na-esonụ: Romo rụrụ nke ọma iji malite oge 2012 ma ghara ikwe ka ọ na-agba ọsọ ruo mgbe May 17, 2012. Mgbe Brian Wilson nwesịrị ịwa ahụ Tommy John n'ọnwa Eprel, e nyere Santiago Casilla ọrụ dị nso. Casilla gbanwere 20 n'ime ohere nchekwa 21 mbụ ya mana ọ gbagburu ise n'ime ọnọdụ nchekwa itoolu na-esote ya, na-ede 7.71 ERA site na June 23 ruo August 7. Bochy kwuputara na August 7 na ndị Giants ga-eji usoro "bullpen site na kọmitii", na Romo, Javier López, na Jeremy Affeldt na-atụgharị n'ime nkeji abụọ ikpeazụ nke egwuregwu dị nso, dabere na ndị na-eti ihe ha ga-eche ihu. Romo na López nwetara ọtụtụ ohere nchekwa; Affeldt nwere naanị otu nchekwa mgbe nke ahụ gasịrị. Site na mgbe ahụ ruo na njedebe nke oge ahụ, Romo gbanwere itoolu n'ime ohere itoolu na-echekwa ma tinye 1.33 ERA. Romo pụtara n'egwuregwu 69 nke oge 2012, na-enweta 14 na-azọpụta na 1.79 ERA, nke bụ nke anọ n'etiti ndị NL na-azọpụta ma na-esochi naanị Craig Kimbrel (1.01), Aroldis Chapman (1.51) na Eric O'Flaherty (1.73). Ọ bụ ezie na ọ ghọrọ onye na-emechi emechi na njedebe nke afọ, ọ meriri onyinye Gibby maka ịbụ MLB's Setup Man of the Year. Ndị Giants meriri NL West; na NLDS megide Cincinnati Reds, Romo pụtara n'egwuregwu atọ, merie Egwuregwu 3 ma chekwaa Egwuregwu 5. O tinyere aka na mmeri anọ niile ndị Giants meriri na
NLCS megide St. Louis Cardinals mana enwetaghị otu ohere ịchekwa. Agbanyeghị, na World Series megide Detroit Tigers, o mere ngosipụta atọ ma dekọọ nzọpụta na nke ọ bụla n'ime ha. Ọ gbara ining ikpeazụ nke egwuregwu nke anọ na-ekpebi ma tie atọ n'usoro, gụnyere Miguel Cabrera maka ọpụpụ ikpeazụ na mmeri ndị Giants. N'asọmpi World Series, Romo gbara ọkpụ atọ n'ụzọ zuru oke ma nwee ọkpụ ise.