School President David Adamany announced the suspension and Atlantic 10 Commissioner Lindo Bruno said Chaney had, "failed to meet his responsibilities."
Upset at what he thought were illegal screens being used by St. Joseph's players Tuesday night, Chaney sent seldom-used Nehemiah Ingram into the game under orders to play rough.
Ingram consistently swung his elbows, fouled out of the game in four minutes and broke the arm of St. Joseph's forward John Bryant.
Chaney apologized the next day and suspended himself for one game. But Adamany suspended him for two more games.
Chaney also yelled at Bruno as he left the court following Tuesday night's contest.
Bruno issued a statement saying that because Chaney was a Hall of Fame coach, he had certain responsibilities.
"In this instance, he failed to meet these responsibilities," Bruno said. "Coach Chaney's actions were completely unacceptable."
She said further incidents would cause, "severe consequences."