Atlanta Thrashers captain Scott Mellanby is expected to announce his retirement Tuesday. The Thrashers have scheduled a telephone news conference for the 40-year-old Mellanby and general manager Don Waddell for Tuesday morning. A team spokesman said Mellanby's future with the team will be discussed. Mellanby had 12 goals and 24 assists in his 21st season, helping to lead the Thrashers to their first playoff berth. It was the 17th time the right winger collected at least 30 points.