Having triumphed in 2005 and 2013, the World No.2 lost to eventual champion Nick Kyrgios in last year's edition. He begins his campaign against compatriot Pablo Andujar, whom he leads 3-0 in career meetings.
Joining Nadal in Acapulco are defending champion Nick Kyrgios and 2019 Acapulco doubles champion Alexander Zverev. Former champion Grigor Dimitrov (2014) and three-time Grand Slam titlist Stan Wawrinka add to the already star-studded list of entrants.
The Next Gen will also be represented in the draw, with Marseille finalist Felix Auger-Aliassime and Australia's Alex De Minaur vying for the title.
Some interesting first-round matches include third seed Stan Wawrinka taking on 2018 Delray Beach champion Frances Tiafoe and Aussie Alex de Minaur facing New York Open semifinalist Miomir Kecmanovic.
2019 champion Nick Kyrgios faces a tough test in 2020 Auckland champion Ugo Humbert. Should the Australian overcome the Frenchman, a potential quarterfinal clash with the in-form Felix Auger-Aliassime awaits.
You can see the whole draw below: