Every day reporters gather around the locker of Packers center Mike Flanagan and ask him about his knees.

"I'm fine," he said. "I'm just tired of answering that question."

The health of Flanagan, a 2003 Pro Bowler who missed 13 games last year because of knee surgery designed to reduce recurring tendinitis, is of primary concern to the Packers.

The quarterback of the offensive line, he scans the alignment of the defenses as he marches out of the huddle. He then barks out the assignment and technique to the other linemen.

"He gets to the line and can change his calls on a dime," guard William Whitticker said. "He makes the right calls and tells us who we're going to block."

Flanagan also instructs them on how to block. With the 40-second play clock winding down, he yells a one-word code, which signifies the proper gap to attack or footwork to use.

Because the rookie Whitticker lines up to his immediate right and Adrian Klemm, a converted tackle who signed as a free agent during the offseason, lines up to his left, Flanagan has taken on an even greater role this year. In 2004 two veteran guards flanked him. Marco Rivera played with the Packers for nine years, and Mike Wahle played with the Packers for seven years before departing as free agents to the Dallas Cowboys and Carolina Panthers, respectively, during the offseason.

Flanagan said last year's offensive line knew the system about as well he did. And he needed to deliver few instructions.

"It'd just be: 'You got it? Yeah, go,'" he said. "Now I need to make sure of the technique and assignments."

If newcomers Klemm and Whitticker or anyone else have questions, they can approach Flanagan. The 10-year-veteran has played with the Packers longer than any other offensive lineman on the roster and is well-versed in the scheme.

"It's second nature," Flanagan said. "I've done it for so long."

He has mastered the offense through hard work. All of the offensive linemen watch film with offensive line coach Larry Beightol, but Flanagan regularly breaks down tape on his own before meeting with the coaching staff.

"There's a lot of things you can take from his daily routine," Klemm said. "He knows everything that's going on."

Flanagan also has impressive physical abilities. His agility allows him to block a defensive tackle lining up wide or a linebacker positioned off of the line of scrimmage.

"Probably one of the most athletic centers in the league, he can make some blocks that others can't," left tackle Chad Clifton said. "He makes it look easier than other centers."

The coaching staff closely monitors those physical skills. In addition to missing 13 games last year, Flanagan missed his entire rookie season in 1996 after suffering a fracture to both bones in his lower right leg while blocking during the opening kickoff of the Packers' second preseason game. He underwent surgery to place a stabilizing rod in the larger bone of his lower leg.

The 31-year-old also missed his second season when muscle and nerves in his leg recovered slowly from his 1996 injury.

After his leg healed, Flanagan became very durable, starting 82 consecutive regular season games before the knee injury sidelined him in 2004.

"He had a pretty serious injury, and to come back from that and be 100 percent is hard," said head coach Mike Sherman, who served as Flanagan's offensive line coach at UCLA in 1994. "He's complained to me of nothing as of late in regards to that injury. He missed a year of football. It's going to take some time to work through some issues."

Flanagan's immediate goal is to have the Packers offensive line play like the unit that surrendered only 15 sacks last year and an NFL-low 68 between 2001 and 2003. They allowed four sacks to the Detroit Lions last Sunday, but Flanagan remains encouraged by the strides of the group.

He singled out the production from the new starters. He said Whitticker has picked up the scheme "amazingly fast" for a rookie and also praised Klemm's understanding of the offense.

"Obviously we're a work in progress," Flanagan said. "Day to day, week to week, they've become more confident in what they're supposed to do and how they're supposed to do it. They've gotten better."

For Flanagan, it's a matter of maintaining his usual high level of play.

"He's as crucial as he's always been." Clifton said. "It's always good to have him back. He's a Pro Bowl player. He's very athletic and he knows the system like the back of his hand."