Croatian Marin Cilic, the former U.S. Open champion and 2017 Wimbledon runner-up, and eighth seed Matteo Berrettini, who lost to Novak Djokovic in the 2021 final, earlier pulled out from the grasscourt Grand Slam ahead of the first round.
Bautista Agut, a former world number nine who was seeded 17th, was due to play Daniel Elahi Galan of Colombia in the second round on Thursday.
"Fortunately, the symptoms are not very serious but I think it is the best decision," Bautista Agut wrote on Twitter hours before his match. "I hope to come back soon."
Galan will play either Canadian Denis Shapovalov or American Brandon Nakashima for a place in the fourth round.
(Reporting by Sudipto Ganguly; editing by Toby Davis)

Roberto Bautista Agut of Spain in action in the men's first round match against Attila Balazs of Hungary at the Wimbledon Championships, in Wimbledon, Britain, 28 June 2022. EPA-EFE/TOLGA AKMEN EDITORIAL USE ONLY