Leach, a third-year pro, started five of 16 games last year for the Packers. He had problems catching passes out of the backfield during training camp this season, which likely was one of the main reasons he was released.
Robinson is expected to join the team for practice, beginning Wednesday.
Henderson, a 12th year pro, is the team's only true fullback. The Packers used David Martin, one of four tight ends on the roster, for a handful of snaps at fullback on Sunday against the Bears. Henderson underwent arthroscopic knee surgery Aug. 21 after he was injured Aug. 19 in a preseason game against Atlanta. He returned to practice last week but was not activated to the game day roster against the Bears.