(Seattle, WA)  --  Kyle Seager's contract extension with the Seattle Mariners is officially a done deal.  The team says the All-Star third baseman will be signed with the Mariners through 2021, with an option for 2022.  The club has not confirmed the reported 100-million figure.  Seager led Seattle last season with 25 home runs and 96 RBI, and a batting average of .268, which was second only to Robinson Cano's .314.