Sopel has one goal and one assist in 23 games for the Blackhawks this season. He has not played since December 20 and must miss at least 30 days on the long-term IR.
The 31-year-old veteran is in his second season with Chicago. He had a goal and 19 assists last season.
In a corresponding move, Chicago activated right wing Adam Burish off injured reserve.
Burish had been sidelined for the past 14 games with a broken toe. He has not registered a point and has picked up 49 penalty minutes in just 19 games this season.