Winkler is best known for his work on the comedy series "Happy Days" and "Arrested Development."
Season 1 concluded with a cliffhanger after Hank learned their father had taken the majority of funds from the brothers' HankMed business.
"Eddie arrives unannounced in the Hamptons, determined to reinsert himself into his sons' lives and make up for lost time. But his motives are unclear at best. He will have a considerable impact on HankMed, as Hank and Evan grow divided over whether family reunions are always something to celebrate," the news release said.
The show focuses on Hank, a disgraced New York physician who reinvents himself as the hot new doctor-for-hire, making house calls any time to anyone in need. Evan is Hank's younger brother and the chief financial officer of HankMed.