Wide receiver Steve Smith yesterday agreed to a three-year contract extension with the Carolina Panthers that will keep him with the team through the 2012 season.

Smith's agent, Derrick Fox, said he was not authorized to release exact figures, but said the Los Angeles native would be among the five highest-paid receivers in the NFL.

The 28-year-old Smith had three years left on a six-year, $27 million contract.

Colts. Gilbert Gardner, a starting linebacker for most of last season, was released by Indianapolis.

The Colts also cut ties with linebackers Mike Labinjo and Brandon Hoyte and defensive back Trevis Coley, and signed tight end Mike Seidman.

Broncos. An autopsy on Denver running back Damien Nash found no drugs or unnatural substances of any kind in his system. An exact cause of death could not be determined, the St. Louis County Medical Examiner's Office said.

Nash, 24, collapsed and died Feb. 24 after a charity basketball game he hosted in St. Louis, his hometown.

A representative from the Medical Examiner's Office said the cause of death was listed as "undetermined."

Giants. Quarterback Eli Manning got one of his off-season wishes when receiver Plaxico Burress showed up for the voluntary conditioning program.

Tight end Jeremy Shockey, however, continues to work out in Florida.

Burress opted to work out in Florida with Shockey the last two off-seasons despite pleas from Manning to attend the workouts at Giants Stadium.