"We have COVID-19 and are in isolation so we do not spread it to anyone else. There are those for whom it could lead to a very serious illness. We are taking it one-day-at-a-time," the 63-year-old Oscar winner wrote in a statement posted on Twitter Thursday.
"There are things we can all do to get through this by following the advice of experts and taking care of ourselves and each other, no? Remember, despite all the current events, there is no crying in baseball."
The baseball line is a famous quote from Hanks' 1992 baseball-themed movie A League of Their Own, which co-starred Madonna, Geena Davis and Rosie O'Donnell as female baseball players in the 1940s. Hanks played their grouchy coach.
The actor also shared in Thursday's tweet a photo of him and his 63-year-old wife casually dressed and wearing baseball caps.