He gets named twice, both times in lists of the war dead. Menelaus tells Telemachus he died wearing another man’s armor, the briefest gesture at the most famous reversal of the Iliad. Demodocus sings of him in the great song of Troy: he fell first and set the rest in motion. The retelling does not retell Homer’s Iliad. It assumes the audience knows or can infer that Patroclus’s death is what pulled Achilles out of his tent and back onto the battlefield, where he killed Hector and was then killed himself. He is a hinge of that earlier story, named here as one of the named dead.
Patroclus
Achilles's beloved. Died at Troy wearing another man's armor. The death that set Achilles back into the war.