Adrian Beltre officially declined his player option for 2011 and hit the open market, according to Peter Abraham of the Boston Globe (on Twitter). Because he reached his plate appearance incentives in Boston, Beltre could have earned $10MM by exercising his 2011 option. As the top free agent third baseman, he is in position to sign for considerably more than that.
Beltre batted .321/.365/.553 this season with 28 homers and a league-best 49 doubles. At 31, he is relatively young and he is considered one of baseball's best defensive third basemen. Only his career .328 OBP and his tendency to play especially well in contract years will limit interest.
If the Red Sox offer arbitration as expected and Beltre turns the offer down to sign with another team, Boston gets two top compensation picks for losing a Type A free agent.