Zherdev is expected to make his regular season debut against the Phoenix Coyotes on Monday night.
The restricted free agent appeared set to play in Russia this season, but the two sides agreed on a US$7.5-million, three-year deal on Sept. 28.
The 21-year-old Ukrainian was second in goals (27) and points (54) with the Blue Jackets last season, his second in the NHL.
Platt played one game with Columbus and did not record a point. The 21-year-old Toronto native led the Blue Jackets in pre-season scoring with seven points (four goals, three assists) in four games.
Platt, who played junior hockey with the Ontario Hockey League's Erie Otters, recorded 65 points (30-35) and 58 penalty minutes in 68 games with Syracuse last season. He also had five assists in 15 games with Columbus.