Rusty Staub is reportedly suffering from kidney failure and is in the Mets thoughts.
Staub, 73, was a popular player across two stints with the Mets in 1972-75 and 1981-85.
"Fred and Jeff Wilpon have each reached out to Rusty to wish him well," the Mets said in a statement. "In addition, multiple people from our organization have been in contact. All of us wish Rusty and his loved ones well in his courageous battle."
Staub, a member of the Mets' 1973 NL pennant-winning team, is a career .279 hitter with 292 home runs.
In 2015, Staub suffered a heart attack while on a flight home from Ireland. He was revived by two doctors on the flight. Just a few days later, he was able to throw out the first pitch at a Mets playoff game.
In 1985, Staub founded the New York Police and Fire Widows' and Children's Benefit Fund. The benefit fund provides money and support for the families of first responders who are killed in the line of duty.