"Now is the time to be responsible and stay at home. These are complicated days for everyone," Messi wrote in Spanish in his post, as translated by the BBC.
Reports published Saturday suggest the Spanish government will declare a state of emergency, locking down the country and requesting that its citizens stay home.
With more than 140,000 confirmed cases of the coronavirus worldwide, social gatherings and sporting events around the globe have been postponed or canceled as experts stress the importance of social distancing.
"We are worried about what is happening and we want to help by putting ourselves in the shoes of those who are getting the worst of it, either because it has directly affected them, their family, or their friends, or because they are working on the front lines to combat it in hospitals and healthcare centers," Messi continued in his post.
"I wish them all plenty of strength," he added. "Health must always come first. This is an exceptional situation and the instructions of both healthcare organizations and public authorities must be followed. This is the only way it can be combated effectively."