Simplify the following text for a Grade 9 native English-speaking person.
Original: On August 2 , 2010 , Turco signed a one-year contract as a free agent with the reigning Stanley Cup champions , the Chicago Blackhawks , replacing Antti Niemi as their starting goaltender .
Simplified: He signed a one-year contract as a free agent with the reigning Stanley Cup champions , the Chicago Blackhawks on August 2 , 2010 .