"You've just got to roll with the punches. You never know what's going to happen. You never know who's going to be available," Spitz said. "So you've just got to go where they tell you."

Asked about how he played against San Francisco, Spitz replied, "Obviously, I was embarrassed at the way we played, but luckily for us, it was during the preseason and hopefully we can learn from it, learn what not to do and move on and get better."

For his part, quarterback Aaron Rodgers said he can't worry about the uncertainty in front of him.

"I'm not concerned at all," Rodgers said. "Spitty's a great center. Guys will step up and play well. The best five is going to be out there."

Drop it like it's hot: There is no grassy-knoll conspiracy for why Donald Driver has dropped a key Rodgers pass in each of the Packers' first two games. Rather, Driver has an easy explanation.

"I just dropped them, plain and simple. Plain and simple," the Packers' two-time Pro Bowl receiver said after practice Monday night.

Against Cincinnati in the exhibition opener, Driver bobbled and dropped a third-down pass on a crossing route to force a punt on the Packers' first possession. Against San Francisco on Saturday night, he was open on a deep ball down the right side and dove for it, the ball caroming off his fingertips incomplete.

"(Rodgers) threw a perfect ball (both times). The first game, I turned my hands the wrong way and dropped it. The second game, I misjudged it and took a dive," Driver said. "We've got to make plays for him. ... Those two plays, I should've made."

Health watch: Linebacker A.J. Hawk said he will miss his second straight game with a chest injury suffered in the opener, and although Hawk wasn't saying what his specific injury is, he did rule out a few things: It's not a torn pectoral muscle, it's not a bruised sternum, and he doesn't need surgery.

Beyond that, Hawk wouldn't say what the injury is exactly, because "I'm just following the rules" on not talking about injuries.

Meanwhile, halfback Ryan Grant, who hasn't played in either of the first two preseason games because of a tight hamstring, said he expects to play, as does wide receiver Greg Jennings (knee), who returned to practice Monday night.

Tight end Tory Humphrey (Achilles' tendon), wide receiver Brett Swain (quadriceps) and tackle Orrin Thompson (ankle) also returned to practice, while defensive tackle Daniel Muir (groin) and tight end Evan Moore (knee) were sidelined by injuries suffered Saturday night. Defensive linemen Ryan Pickett (hamstring), Justin Harrell (back) and Kabeer Gbaja-Biamila (knee) did not practice, although KGB was in pads and worked in the Hutson Center.

Everything but the kitchen sink? The smile on Rodgers' face said all you needed to know about how he felt about the theory that the 49ers game-planned for him and blitzed him more extensively because coach Mike Nolan didn't want Rodgers to play well after bypassing him to take struggling Alex Smith with the No. 1 overall pick in the 2005 draft.

"I don't know, you'd have to ask the 49ers," Rodgers replied. "If I was Mike Nolan, I would've kept blitzing, too, because we couldn't figure it out."

When asked how many corner blitzes like those that the 49ers ran in the first quarter he'd seen in his previous three preseasons, Rodgers admitted, "Probably never."

The end zone: Offensive coordinator Joe Philbin was gone Monday because of a death in the family. ... Cornerback Joe Porter was also missing because of a personal matter. ... The players moved out of the St. Norbert College dorms on Sunday. ... Former GM Ron Wolf is visiting practice this week. ... McCarthy said Brian Brohm "is still ahead" of Matt Flynn in the backup quarterback race. ... Players spent two hours starting at 10 a.m. watching film of the 49ers game, then began their preparation for Denver. ... McCarthy was not overly critical of cornerback Jarrett Bush's play against the 49ers, despite Bush allowing several long completions.