The 49ers' offensive line played poorly last season, yielding a franchise-record 55 sacks. Although there are no newcomers slated to start, the 49ers have only one lineman - center Eric Heitmann - returning as the primary starter at the same position as a year ago.

In the exhibition opener, the starting left side of the offensive line did not fare well. Left guard Adam Snyder and left tackle Joe Staley were beaten several times in pass protection, and their run blocking was not up to par, either.

"I would like for them to do better than they did last night," Nolan said. "I thought we started a little bit soft. We can get better than that. They will be fine. They had good plays and bad plays, but they can get better."

The 49ers' best offensive lineman during camp has been right tackle Jonas Jennings, who was moved over from left tackle in the offseason. Jennings has played just 21 games in three seasons with the 49ers after signing a seven-year, $36 million contract in 2005.

"The last few years it's been a difficult situation for us because Jonas has been nicked up," Nolan said. "When that happens to your left-tackle position it's difficult on your offense."

It's also been difficult on Jennings, who has been the subject of rampant rumors and innuendo about the reason for a one-game leave of absence last season, as well as his standing inside the team's locker room.

"If I was that big of a problem - if any of that was true -- why am I still around?" Jennings said. "You have to add it up for yourself. You know what I'm saying?"

At right guard, the 49ers have David Baas penciled in to start opening day on Sept. 7 against the Arizona Cardinals. However, he sustained a torn pectoral tendon while lifting weights in April and is not expected to participate in training camp. Veteran Tony Wragge looks to have the clear edge to start the season ahead of second-round draft pick Chilo Rachal if Baas is not ready for action.

CAMP CALENDAR: The 49ers practice most mornings, beginning at 8:50 a.m. Every other day, they have a second full-squad practice in the afternoon. On the other days, they hold special-teams practices in the afternoon. The 49ers break camp on Aug. 22, the day after an exhibition game at the Chicago Bears.