The team made the announcement via its Twitter page. No other details were released.
Stafford was second on the Sabres during the regular season with 31 goals and tied for third with 52 points -- both career highs -- despite missing 20 games with injuries. He also posted a career-best plus-13 rating.
The Sabres took Stafford in the first round (No. 13 ) in the 2004 Entry Draft. He has 94 goals and 196 points in 317 game over five seasons with Buffalo.