Wideman had two goals and five assists in 25 games with the Ottawa Senators, Edmonton Oilers and Florida Panthers last season. The 29-year-old has 45 points (16 goals, 29 assists) in 181 regular-season games.
De Leo, who had a salary arbitration hearing scheduled for July 27, has no points in three NHL games with the Ducks and Winnipeg Jets. The 23-year-old had 55 points (20 goals, 35 assists) in 66 games with San Diego of the American Hockey League last season.
Kloos has no points in two NHL games with the Ducks and Minnesota Wild. The 25-year-old had 45 points (18 goals, 27 assists) in 59 games with San Diego and Iowa of the AHL last season.