Brent Sopel apparently has made a positive impression on the Blackhawks. The Blackhawks on Thursday signed the defenseman to a three-year contract extension. Financial terms were not disclosed, but TSN of Canada reports the deal to be worth $7 million. Sopel originally had agreed with the Blackhawks on a one-year contract in September. In 33 games this season, Sopel has registered 10 assists and a plus-10 rating.