Hayes, 32, played in 29 games for the Toronto Raptors last season, averaging 8.8 minutes per game. Hayes averaged just 1.7 points and 1.8 rebounds per game.
Hayes is familiar with the Rockets, having spent the first six seasons of his NBA career in Houston.
The Rockets are also in talks with veteran guard Jason Terry about a possible return. Terry, 37, had the most playoff experience of any Rockets' player last season and moved into the starting point guard role when Patrick Beverley suffered a season-ending wrist injury.