Green was placed on injured reserve today, shelving him for the rest of the season following his second severe concussion in 13 months.

The 37-year-old said he has made no decision about playing next year. A series of test results were normal following the latest injury Oct. 7, but doctors were concerned about possible long-term effects and declined to clear him to play.

By putting Green on injured reserve, the winless Dolphins freed up a spot on the 53-man roster, which they used to activate receiver Kerry Reed from the practice squad.

"At this point, this is the best thing for Trent and the team," coach Cam Cameron said in a statement. "The doctors have prescribed rest for now. No long-term decisions regarding Trent's future have been made."

Green said he understood the Dolphins' need to make a move.

"I appreciate the way the organization has handled this," he said in a statement. "I realize this is in the best interest of my long-term health, and I want nothing but the best for the team. Right now I haven't made any decisions about my future, but I talked with the Dolphins about staying involved in some capacity the rest of the season."

Green has been a mentor to rookie John Beck, a second-round draft pick who may soon be given a chance to show whether he's the Dolphins' quarterback of the future. Cleo Lemon will make his third NFL start tomorrow for Miami (0-6) against New England (6-0).

Since the retirement of Dan Marino following the 1999 season, Miami has used 11 starters at the position.

Green threw to receivers on the side at practice this week. He said he felt fine and had no dizziness or other symptoms associated with concussions, and he wanted to play again.

But he acknowledged the decision was up to doctors.

Green considered retirement when a concussion in September 2006 sidelined him for eight games with the Kansas City Chiefs. The effects of the latest injury were less serious, he said, although it left him unconscious for at least 30 seconds.

Green started every game for the Chiefs from 2001 to 2005, twice made the Pro Bowl and threw for more than 4,000 yards three years in a row. But he wasn't the same when he returned from his concussion last year, throwing for only seven touchdowns with nine interceptions in eight games.