It was Ballesté (2017) who named this artist the Master of Philadelphia. The name comes from the two panels in the Philadelphia Museum of Art: Hunting the Ox on Mount Gargano and The Episcopal Procession on Mount Gargano, which would be joined by Apparition of the Ox in the Cave of Mount Gargano, a painting in a private collection in Italy. Although originally attributed to the Master of Palanquinos, Ballesté (2017, 2019) did not consider them works by the latter due to the absence of languor and the canon so characteristic of the master. Likewise, Ballesté (2017) argued that the Master of Philadelphia had "something of the master collaborator of the altarpiece of Santa Marina de Asturias and of the Salamancan Fernando Gallego, but enjoys at the same time an anatomical canon and an expressiveness a little more restrained than those developed by both painters."
BALLESTÉ ESCORIHUELA, Marc (2017): De la pintura Hispano-flamenca al primer Renacimiento en las antiguas diócesis de León y Astorga: El Maestro de Palanquinos y el Maestro de Astorga (c. 1480-1540), Universidad de Lleida (Tesis doctoral), Lleida, pp. 109-111.