Diablos Rojos del México Fernández led the Diablos Rojos to the first place of the Mexican League South Division with a 66–39 record. The team swept the
Piratas de Campeche 4–0 in the first round of the playoffs, then defeated the
Leones de Yucatán 4 games to 2 in the South Division championship series. The Diablos went on to beat the
Sultanes de Monterrey 4–1 in the
Serie del Rey, claiming the
2008 Mexican League championship -the fifteenth in their history- in Fernández's debut season as manager. He won the Manager of the Year Award. The Diablos Rojos finished the
2009 regular season first in the North Division with a 70–35 record. However, they were swept in four games by the
Vaqueros Laguna in the first round of the playoffs. In November of that year, Fernández was dismissed as manager of the Diablos and replaced by
Mako Oliveras.
Olmecas de Tabasco On 23 March 2010, just five games into the
2010 Mexican League season, Fernández was appointed as manager of the
Olmecas de Tabasco, replacing
Gustavo Llenas, who had started the season with an 0–5 record. After 21 games and only five wins, Fernández was removed as manager of the Olmecas and replaced by
Enrique Reyes.
Rojos del Águila de Veracruz In November 2010, Fernández was named manager of the
Rojos del Águila de Veracruz, ahead of the
2011 season. The team finished the season third in the South Division with a 103–54 record. They lost the South Division championship series 2–4 to the
Tigres de Quintana Roo, that went on to win that year’s Mexican League title. He did not stay with the team and was replaced by
Orlando Merced.
Leones de Yucatán On 21 November 2012, Fernández was appointed manager of the
Leones de Yucatán for the
2013 season. On 2 May 2013, he was sacked along hitting coach
Juan Carlos Canizales due to poor results, as the Leones had 17–17 record. He was replaced by
Marco Antonio Guzmán.
Vaqueros Laguna On 7 May 2016, Fernández replaced
Vicente Palacios as manager of the
Vaqueros Laguna. Palacios had served as interim manager for seven games, leading the team to a 4–3 record, after replacing
Mario Mendoza, who was fired following an 11–13 start. Vaqueros Laguna finished the season in fourth place in the North Zone. In the playoffs, they were swept in the first round in four games by the
Sultanes de Monterrey. On 22 September 2016, Fernández was removed as manager of the team.
Piratas de Campeche In December 2017, Fernández was appointed manager of the
Piratas de Campeche ahead of the 2018 season, that was played in a two-tournament format. In the first tournament, the Piratas finished with a 22–34 record, failing to qualify for the playoffs. On 30 July 2018, 24 games into the second tournament, Fernández was sacked with a 10–14 record; he was replaced by hitting coach
Rómulo Martínez as interim manager.
Guerreros de Oaxaca On 9 August 2018, Fernández joined the
Guerreros de Oaxaca as bench coach under manager
Sergio Omar Gastélum. On 7 July 2023, Fernández was appointed interim manager of the Guerreros, replacing
Gerónimo Gil, who was fired after a 24–36 record. He led the team to a 34–53 finish, placing seventh in the South Division and failing to qualify for the playoffs.
Academia Alfredo Harp Helú Fernández has worked as a coach in the Academia Alfredo Harp Helú, a baseball academy in
San Bartolo Coyotepec,
Oaxaca that serves as feeder for the Diablos Rojos del México and Guerreros de Oaxaca. ==Legacy==