The contract carries an average annual value of $2 million, according to Sportsnet's Chris Johnston.
The Red Wings have already signed Bobby Ryan, Troy Stecher, Jon Merrill, and Thomas Greiss since the opening of the free agency period on Friday. General manager Steve Yzerman previously drafted Namestnikov in the first round of the 2011 NHL Draft with the Tampa Bay Lightning.
The 27-year-old appeared in 65 games last season with the New York Rangers, Ottawa Senators, and Colorado Avalanche. He totaled 17 goals and 14 assists.
Namestnikov has played in 425 career games, amassing 83 goals and 106 assists.