The 33-year-old has appeared in 381 career NHL games — only five of which came in the last two seasons.
The two-way contract means Willsie can be shipped back and forth between the NHL and American Hockey League.
He finished 11th in AHL scoring a year ago by putting up 68 points (30-38) in 76 games for the Hershey Bears. He had an assist in one game for the Washington Capitals.
Willsie is a former seventh-round pick by Colorado in 1996 and has scored 52 goals and 109 points in his 318 career NHL games for Washington, Los Angeles and Colorado.