Aguero made his return from a thigh injury as an 82nd-minute substitute in Wednesday's semifinal win over the Netherlands and even scored from the spot in the subsquent penalty shootout.
However, the Manchester City striker has only been deemed fit enough for a place on the bench, with Ezequiel Lavezzi once again getting the nod on the right-hand side of the Albicelste attack.
Di Maria, meanwhile, has not featured since suffering a thigh problem of his own 33 just minutes into the quarterfinal win over Belgium but had sparked hopes of a return after participating in some light training sessions in recent days.
Alejandro Sabella has decided against taking a risk on Di Maria from the start, though, meaning Enzo Perez will continue to deputize for the Real Madrid man.
Germany, meanwhile, has unsurprisingly stuck with the same starting XI that humiliated host Brazil in the semifinals.
Germany (4-2-3-1): Neuer; Lahm, Boateng, Hummels, Howedes; Khedira, Schweinsteiger; Muller, Kroos, Ozil; Klose.
Argentina (4-2-1-3): Romero; Zabaleta, Demichelis, Garay, Rojo; Biglia, Mascherano; Messi; Lavezzi, Higuain, Perez.