Adelman, who has held the same post with Sacramento, Golden State, and Portland, was called the Plan B choice in a report Wednesday by the Houston Chronicle if Van Gundy does not come back.
In 16 seasons, the 60-year-old Adelman is 752-481 with 14 playoff appearances and four division titles.
Van Gundy is 430-318 in 11 seasons, including 182-146 in four seasons with the Rockets, where his post-season record is 40-44.
Several reports have after a recent first round playoff loss against Utah that Van Gundy has pondered retirement. He is under contract with Houston for another season.
The Chronicle report said Rockets assistant coach Tom Thibodeau is the leading candidate should there be an opening and team General Manager Daryl Morey told the newspaper that Van Gundy is "aware of the process."