The post showed a plush kangaroo toy holding the Australian flag next to Hanks' breakfast of Vegemite on toast.
"Thanks to the Helpers. Let’s take care of ourselves and each other. Hanx," the actor wrote in the post.
Hanks and Wilson have been in isolation in Australia since testing positive for COVID-19, according to the two-time Oscar winner's Instagram account.
Sunday's post was the second update from Hanks since his initial post about testing positive.
Hanks, 63, first announced his diagnosis on Wednesday, saying that while in Australia, he and Wilson came down with symptoms resembling a cold, as well as body aches and slight fevers.
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"To play things right, as is needed in the world right now, we were tested for the Coronavirus, and were found to be positive," Hanks wrote.
In his first Instagram update following that post, Hanks thanked those who had helped them while in isolation in Australia and asked people to take care of one another.
"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," Hanks said, referencing his classic line the film "A League of Their Own."
Hanks is in Australia for preproduction of an untitled film about Elvis Presley, according to the entertainment website Deadline.