In 1988 Díaz was appointed CD Lugo manager. He was sacked the following year, but eventually returned to the club in 1990.
In 2000, after a stint at Pontevedra CF, Díaz returned to the Albivermellos, and despite leaving the club at the end of the campaign, was again appointed on 19 September 2001.[2] He was sacked in December 2002, and ended his spell at the club with 214 matches in charge, behind only Quique Setién.[3]
On 14 March 2007, Díaz was named SD Negreira manager.[4] Roughly one year later, he was dismissed.[5]