Niners fill Spencer’s roster spot with O-lineman

The 49ers claimed offensive lineman Kirk Barton off waivers today to take cornerback Shawntae Spencer’s spot on the 53-man roster.

Spencer sustained a torn ACL on Sept. 14 against the Seahawks, but had remained on the roster for the past four weeks. He was placed on injured reserve today, officially ending his season.

Barton (6-4, 305) was a seventh-round pick of the Chicago Bears in 2008 draft. He was a four-year starter at Ohio State. He appeared in 47 games, including 40 starts at right tackle. He played for the North squad in the Senior Bowl.

The Dolphins waived Barton on Wednesday to sign fullback Lousaka Polite. The Dolphins claimed Barton off waivers from the Bears on Sept. 12.

Barton is scheduled to join his new teammates at the team hotel in New Jersey on Friday evening. He will not suit up for the game.

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INJURY REPORT: Linebacker Manny Lawson (hamstring) was limted in practice, but coach Mike Nolan said he’d be probable for Sunday’s game against the Giants. At the time of Lawson’s injury, Nolan said the plan was to get more playing time for Lawson. When asked today about that plan, Nolan said, “If his health permits, that’ll be the case.”

Tackle Jonas Jennings did not practice and will not play in Sunday’s game. Safety Mark Roman (knee) and cornerback Donald Strickland (hip) saw limited practice.

For the Giants . . . linebackers Antonio Pierce (quad) and Gerris Wilkinson (knee) did not participate in practice. Center Shaun O’Hara (toe) returned to full practice.

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Toward the end of practice, the 49ers went starters vs. starters in their two-minute drill. The two-minute section is tentatively scheduled for every Thursday, Nolan said. Sometimes they do it; other times they do not.

Nolan said it’s ones vs. ones because it’s more beneficial that way, rather than holding two separate two-minute drills.

There was a brief altercation late in practice involving Joe Staley and Roderick Green. Nolan’s standard answer when asked about practice-field fisticuffs is that tempers flare only when it’s important to them.

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