SAN DIEGO -- The San Diego Chargers placed left tackle Jared Gaither on injured reserve Friday, ending an unproductive season for a player expected to shore up a shaky offensive line.

"We've given Jared Gaither every opportunity to be a part of this team and it just hasn't worked out," said coach Norv Turner, who clearly was disappointed at the way the lineman's season has gone.

"Obviously, physically, he hasn't been able to be part of it."

Asked if he was happy with the work ethic of the 6-foot-9, 335-pound Gaither, the coach said: "It is what it is. There's not really a lot left to be said about it."

Gaither played in only four games this season. He missed almost all of training camp and the first three games with a back injury. He injured his groin late in a loss at New Orleans and played in only two games since.

In the closing seconds of the Saints game, with the Chargers desperately trying for the tying touchdown, Martez Wilson blew past the hobbled Gaither on Philip Rivers' blind side for a strip-sack and recovered the fumble to preserve the Saints' 31-24 victory.

Gaither was signed off waivers after Marcus McNeill was hurt late last year, and played well in the final five games. The Chargers gave Gaither a four-year, $24.5 million contract in March.

Rivers has been under siege most of the season because of the line's poor play. Adding to San Diego's woes was the retirement of left guard Kris Dielman due to a concussion.

Rivers has thrown 14 interceptions and lost four fumbles this season, giving him 43 turnovers since the start of the 2011 season.

Undrafted rookie Mike Harris has filled in for Gaither, and will have to face Terrell Suggs of the AFC North-leading Baltimore Ravens on Sunday.

"I don't know what we would have done without him," Turner said about Harris. "He's a guy who's improved and working as hard as he can. He's been in some tough matchups and he's managed to the best of his ability."

Asked if he'd like to see Gaither back next year, Turner said: "You know, we're going to start getting those questions about a lot of things. I'm interested in doing what we can to give this team the best chance to win the Baltimore game. Obviously, after that we move on to the next opponent."

Turner is expected to be fired if the Chargers miss the playoffs for the third straight season. At 4-6, the Chargers have all but ceded the AFC West title to the Denver Broncos and are a longshot to secure a wild-card berth.

The Chargers are expected to sign tackle Kevin Haslam from the practice squad to the active roster.