Niners feel a blitz coming on

SANTA CLARA — On paper, it’s the worst matchup possible for the 49ers on Sunday.

The 49ers have surrendered a league-worst 20 sacks in five games. The Philadelphia Eagles lead the NFL with 18 sacks, coming from 11 different contributors.

The pressure will be on the 49ers’ pass protectors on Sunday at Candlestick Park, as Eagles defensive coordinator Jim Johnson has an affinity for bringing extra pass rushers. The Eagles have gotten 6.5 sacks from their linebackers and defensive backs.

“They do a lot of blitzing, so obviously on offense, the offensive line in particular will be challenged,” 49ers coach Mike Nolan said.

Niners linebacker Takeo Spikes spent last season with the Eagles. He knows all about Johnson’s aggressive defensive approach.

“If he sees any indication from any part of the game where you can’t handle the blitz, you pretty much have to expect that,” Spikes said. “That’s his mentality. We blitzed a lot. A lot depends on whether you show me you can pick it up.”

Quarterback J.T. O’Sullivan will undoubtedly feel the heat on Sunday. The New England Patriots sacked him just once last week, but O’Sulllivan was forced to leave the pocket to scramble five other times when he sensed protection breaking down.

“You can’t help but be conscious of it,” O’Sullivan said of the Eagles’ tendency to blitz in passing situations.

One of the oddities of offensive coordinator Mike Martz’s system is that there are very few audibles. There are rules built into every play that outline automatic adjustments to be made depending on what the defense shows.

“There’s not, ‘Well, this is our answer. If they blitz, we’re going to do this.’ Every play has its own answer,” O’Sullivan said. “The thing we have to do is understand our job, and what that answer is all the time.”

The 49ers have done a good job this season of capitalizing on big plays down the field. They rank tied for fourth in the league with 21 plays — including 17 pass plays — of 20 yards or more.

“There’s always a chance to make a big play,” 49ers center Eric Heitmann said. “If we make the adjustments against their blitz, huge plays can open up.”

Three Eagles starters will not play Sunday due to injuries, including running back Brian Westbrook. Coach Andy Reid ruled out Westbrook (ribs), receiver Reggie Brown (groin) and guard Shawn Andrews (back) for the game against the 49ers.

“It’s kind of like us without Frank Gore, I guess you could say,” Nolan said of Westbrook’s absence. “But by no stretch are we going to take Philadelphia lightly. They’re an outstanding football team, as everyone knows.”

The Eagles will turn to Correll Buckhalter, who has carried 30 times for 114 yards and a touchdown this season.

Receiver Kevin Curtis, who missed the first five games with a sports hernia, is expected to return to action. His return could compensate for the loss of Brown, who has 10 catches for 163 yards in three games.

Linebacker Manny Lawson (hamstring) did not practice and is doubtful for Sunday’s game. Tackle Jonas Jennings (shoulder) will not play. Jennings has not played since Sept. 14.

Linebacker Roderick Green (stomach virus) practiced Friday, but is listed as questionable. Green was a healthy scratch from last week’s game, as Tully Banta-Cain saw his first playing time of the season. Banta-Cain is expected to be in uniform again for Sunday’s game.

For more on the 49ers, go to Instant 49ers at 49ers.pressdemocrat.com. You can reach Staff Writer Matt Maiocco at 521-5492 or matt.maiocco@pressdemocrat.com.