Pyatt had one assist, 10 penalty minutes and a minus-9 rating in 22 games this season before the Rangers placed him on waivers Wednesday.
The past two seasons in New York Pyatt, 32, had six goals and six assists in 70 regular-season games and two goals and two assists in 12 Stanley Cup Playoff games, all in 2013.
Taken by the New York Islanders with the eighth pick of the 1999 NHL Draft, Pyatt has 136 goals and 276 points in 825 NHL regular-season games with the Islanders, Buffalo Sabres, Vancouver Canucks, Phoenix Coyotes and Rangers. His best season was 2006-07 with Vancouver, when he had a career-best 23 goals.
The Penguins host the Rangers Friday night at Consol Energy Center.