"Dan is looking forward to beginning an intensive rehabilitation program and is eager to continue the progress he has made over the last several weeks," Quicken Loans CEO Jay Farner said in a statement.
Gilbert, who was discharged Wednesday, will undergo his rehabilitation at an an in-patient center.
The 57-year-old purchased the Cavaliers in 2005, and under his watch, the organization won the NBA title in 2016 and reached the Finals five times.
He also infamously wrote an incendiary open letter to the city of Cleveland and Ohio in general after LeBron James left for the Miami Heat in 2010, calling James' televised announcement a "several day, narcissistic, self-promotional build-up culminating with a national TV special of his 'decision' unlike anything ever 'witnessed' in the history of sports and probably the history of entertainment."
Gilbert also guaranteed that the Cavaliers would win a title before James won one with Miami, though James and the Heat won titles in 2012 and 2013.
But the two patched things up before LeBron's return in 2014, and James, Kyrie Irving and Kevin Love led the organization to its first title two years later.
James left again last summer, and the Cavaliers have undergone a rebuild around young point guard Collin Sexton. Love remains on the team, though he's a potential trade candidate for the young Cavaliers, who also hold the No. 5 pick in Thursday's NBA draft.