The 33-year-old winger is expected to arrive in Moscow on Sunday to strengthen the lineup for Finland, which beat Ukraine 5-0 Friday in its opening game.
The Stars were eliminated Tuesday by the Vancouver Canucks in the first round of the NHL playoffs. Lehtinen scored 26 goals and 17 assists for Dallas this season.
Lehtinen won the Stanley Cup with the Stars in 1999. He also helped Finland secure its first-ever IIHF world championship gold medal in 1995, and Olympic bronze in 1998 and silver in 2006.