Euro 2025 in Switzerland starts on Wednesday and Spain play Portugal in their opening Group B game in Bern on Thursday.
“Thanks to everyone for the messages I’ve received and to those who have helped me these past few days,” two-time Fifa women’s player of the year Bonmati wrote on Instagram.
“Fortunately, everything is going well. I hope to be back soon.”
Bonmati has scored 30 goals in 78 games for Spain and was a key member of the side that won the 2023 World Cup and the Nations League last year.
Speaking before Bonmati left hospital, Spain coach Montse Tome said: “She is a very important player for us. We’ll wait for her as long as we can.”
Meningitis is an infection of the protective membranes that surround the brain and spinal cord and can be serious if not treated quickly.
According to the NHS, external viral meningitis is less serious than the rarer bacterial meningitis. It tends to get better on its own within seven to 10 days and can often be treated at home.