Forwards Ray Whitney, Vernon Fiddler and Ryan Garbutt, and defenseman Stephane Robidas are scheduled to become unrestricted free agents July 1 and could be moved by the March 5 trade deadline.
Veteran defenseman Sergei Gonchar has also been reportedly mentioned as trade bait.
Robidas owns a full no-trade clause and can have a say on where he ends up being traded to, if at all.
The native of Sherbrooke, Quebec, broke his leg in late-November and won't be back in action until March, at the earliest. He's enjoyed his time in Dallas and could look to sign an extension with the club.
The Stars are entertaining calls for Whitney, Fiddler, Garbutt and Gonchar, all of whom could be dealt by the March 5 trade deadline.
Whitney owns a limited no-movement clause and can list up to 10 teams he will not accept a trade to. According to published reports, he would be open to a trade, and could be shipped to a Stanley Cup contender in the coming weeks.
Fiddler, who requested a trade earlier in the season, but later changed his mind, could ultimately get his wish by the deadline.
The Stars also have plenty of salary cap space and Nill will be looking to improve his club this season and in the summer.
With center Tyler Seguin and left wing Jamie Benn leading the charge up front, Nill wants to add secondary scoring to his roster, as well as sound, defensive-minded players on the backend.
The Stars rank 25th in the NHL in goals-against per game, an area the team wants to significantly improve upon for next season.