Ira Winderman of the South Florida Sun-Sentinel reports:

And then there were three.

Heat to exercise Chalmers option

Point guard Mario Chalmers has become the third Miami Heat player secured on the books for 2010-11.

While neither side would confirm the formal paperwork has been completed, the Heat has informed Chalmers that it will pick up the option year on his rookie contract.

The Heat had until June 24, the day of the NBA Draft, to make its decision.

Chalmers now joins forward Michael Beasley and guard Daequan Cook as the only Heat players locked into 2010-11 salaries.

Still to be determined is the player option held by center Joel Anthony, who also faces a June 24 deadline, as well as a buyout decision on the final three years of the contract of forward Jabmes Jones, and guard Dwyane Wade’s decision on his 2010-11 option year.