SANTA CLARA -- The San Francisco 49ers put left tackle Jonas Jennings on injured reserve Monday with an ankle injury, and right guard Justin Smiley might soon join him with a torn labrum in his right shoulder.
After six straight losses heading into the regular season's midpoint, the injury diagnoses were even more bad news for the 49ers (2-6), who seem likely to finish the year without two linemen who have been starters ever since coach Mike Nolan took over the club.
"It's unfortunate to lose any player on our team," Nolan said.
"But at the same time, I have confidence in the guys stepping in."
Jennings has a lingering ankle injury that requires surgery, Nolan said while announcing the end of another disappointing season for his oft-injured lineman.
Jennings missed the 49ers' last two games after spraining his ankle in a loss to the New York Giants.
Smiley, a fourth-year pro who has started every game in the 49ers' last 2½ seasons, dislocated his right shoulder and tore his labrum when Atlanta's Trey Lewis landed squarely on his arm as Smiley dived to recover a fumble in the 49ers' 20-16 loss to the Falcons.
An MRI revealed a torn labrum that will be inspected by Dr. James Andrews in Birmingham, Ala., today before Smiley decides to have season-ending surgery. The noted orthopedist has been the source of Smiley's most reliable medical advice since his college days at Alabama.
"If (Andrews) thinks it's the thing to do, we'll go ahead and knock it out," Smiley said. "It needs to be done."
Smiley played 14 games with a torn left labrum last season, but his latest injury is much more severe. Team doctors needed about 20 minutes to get Smiley's arm back in its socket in Atlanta.
Losing two starters will test the depth of the 49ers' once-solid offensive line, which has failed to mount a significant rushing attack with running back Frank Gore this season. Gore sat out Sunday's game with a sprained ankle, but is expected to return for San Francisco's trip to Seattle on Monday night.
Nolan said Adam Snyder will stay in his role as Jennings' replacement at left tackle, keeping Joe Staley waiting on the other end of the line.
San Francisco sacrificed its first-round draft pick in 2008 to trade up last April to draft Staley, who's currently learning the NFL ropes at right tackle. The 49ers believe Staley could be their long-term left tackle, usually considered the line's most important position.
David Baas, the 33rd overall pick in the 2005 draft, will replace Smiley. Baas has played extensively as a backup in his first 2½ years with the 49ers, but never landed a full-time starting job.
JANO WANTS ANOTHER SHOT -- A day after he missed setting an NFL record when his kick bounced off the upright, Sebastian Janikowski said he's ready to try an even longer kick than the 64-yarder that he missed.
"I'll kick whatever," Janikowski said Monday. "I don't care if it's 80 yards. I want to attempt it. As long as I'm not short."
Janikowski came within inches of breaking the record of 63 yards held by Tom Dempsey of New Orleans and Jason Elam of Denver when his kick late in the first half smacked off the right upright.
"It was going straight and the last 10 yards or so it turned a little bit," Janikowski said. "I thought it was going to hit the goal post and go in but I guess it hit the goal post going away."