From the estimable Vultus Christi:
Yes, that would be the much loved Saint Juan Diego of Guadalupe as he is designated in the new Solesmes Antiphonale Monasticum for December 9th. Here is the official Collect for his feast with my English translation:
Deus, qui per beatum Ioannem Didacum,
sanctissimae Virginis Mariae dilectionem
erga populum tuum ostendisti:
eius nobis intercessione concede,
ut, Matris nostrae monitis Guadalupae datis obsequentes,
voluntatem tuam iugiter adimplere valeamus.O God, Who, through Saint Juan Diego,
didst show forth the special love of the Most Holy Virgin Mary
toward Thy people,
at his intercession, grant us
so to obey the admonitions given by our Mother of Guadalupe,
that we may ever be able to fulfil Thy will.
