Mangini, who reportedly cut short a Saturday practice because of inclement weather, said the injury Steptoe sustained wasn't a result of field conditions or the nature of the drills.
''Seventy-nine other guys were able to practice effectively," Mangini said Sunday. "And really the play that he was injured on didn't have anything to do with the elements."
Steptoe's season was ended when he suffered a torn labrum, his agent, Jerome Stanley, told the Cleveland Plain Dealer.
"The coaches should more carefully weigh the risk of injury in practice decisions,'' Stanley said.
Stanley blamed the injury on a change of plans from walk-through drills, which he said the players had expected, to a full-speed practice in heavy rain.
''I haven't talked to Syndric Steptoe's agent. I don't know what he said,'' Mangini said. ''The practice we had planned is the practice that we executed Saturday.''
Mangini said Steptoe was diving for a pass when he was hurt. It was a move Steptoe commonly attempts in drills, according to the coach.
''He really laid out for the ball," Mangini said. "It was a great effort play; he just couldn't bring it in.''