Dan Gilbert has been hospitalized in Michigan.
The Cavaliers' majority owner was admitted to Royal Oak Beaumont Hospital after showing symptoms of a stroke, The Detroit News reported Sunday.
Gilbert's company, Quicken Loans, later issued a statement.
"Early this morning, Dan Gilbert sought care at a local hospital after experiencing stroke-like symptoms," the statement read. "He received immediate medical attention and is currently recovering comfortably. Our collective thoughts and prayers are with Dan for a speedy recovery. The Gilbert family respectfully requests privacy at this time."
The specifics of Gilbert's diagnosis were not released, according to The Detroit News.
Gilbert, a Detroit native, became Cleveland's majority owner in 2005. Since then, the Cavaliers have won their only NBA championship in 2016, behind the leadership of now-Lakers star LeBron James.
Cleveland finished 2018-19 with a 19-63 record, which was tied for the second-worst mark in the NBA. It has the fifth pick in the 2019 NBA Draft.