Dillon Ward's five-year agreement ties a franchise record.
Dillon Ward is a finalist for the 2014 NLL Rookie of the Year award.
The Mammoth owns the fourth overall pick in the draft.
2008 NLL MVP Athan Iannucci has agreed to terms with the Mammoth to return next season.
Mammoth coach Pat Coyle (L) was one of two NLL Hall of Fame inductees on Wednesday.