Green Bay, Wis. ? Pass protection is and probably always will be the most important part of the job for an offensive tackle in the National Football League.

Left tackle Chad Clifton and right tackle Mark Tauscher have protected and still do protect Brett Favre very well since they moved into the Green Bay Packers’ lineup as rookies in 2000.

Coach Mike McCarthy, offensive coordinator Joe Philbin and line coach James Campen know that, value that and factor that into any evaluation of their two veteran tackles.

But when a team’s running game ranks dead last in the NFL and every day brings more questions, it gets harder and harder for coaches to remember what Clifton and Tauscher do in protection and ignore their shortcomings as run blockers.

Tonight, the Packers will play in Denver, the birthplace of the zone run game that they installed in 2006. Despite losing two starting offensive linemen, the Broncos still rush for 130.7 yards each week behind a unit led by left tackle Matt Lepsis.

“Very good, very active,” Campen said when asked about Lepsis. “He gets flat down the line on the back side and makes cuts. He’s quick to the aiming point. Not a real overly powerful guy, but he busts his butt and he finishes.”

Lepsis, 33, started at right tackle from 1999-2003 before moving to the left side in ’04. At 6 feet 5 inches and 290 pounds, he epitomizes the long, lean blockers that retired line coach Alex Gibbs built his zone scheme around in Denver.

Clifton (6-5, 319) and Tauscher (6-31â2, 316) were drafted at a time when the Packers’ ground game under Mike Sherman was based on power. The tackle would block down, and the guard would pull around to clear a lane for Ahman Green.

Neither Clifton nor Tauscher ever was regarded as an elite run blocker. Still, they more than held their own.

For a year and a half, McCarthy and his coaches have preached how wonderful the zone scheme would be. But it didn’t work last year with Green, and it hasn’t come close to working this year with much lesser backs.

The linemen basically were the same last year and this year. Also the same is their unacceptable performance as run blockers.