The Packers’ draft-and-develop philosophy is on the fast track at the offensive tackle position.

Veteran left tackle Chad Clifton’s hamstring injury is “significant,” Head Coach Mike McCarthy announced on Monday, and he’ll be out “for a number of weeks.” Clifton went down in the second quarter in Atlanta on Sunday night, and the medical staff has told McCarthy it may be a couple of weeks before there’s any timetable for a possible return.

That leaves 2010 first-round pick Bryan Bulaga, 2010 fifth-round pick Marshall Newhouse and 2011 first-round pick Derek Sherrod as the entirety of the Packers’ depth at tackle for the foreseeable future.

Bulaga has missed the past two games with a knee injury and McCarthy expects to find out Tuesday whether he’s cleared to return to practice this week. Newhouse had been filling in for him but he flipped to left tackle to take Clifton’s place in Atlanta while Sherrod stepped in at right tackle.

If Bulaga isn’t back this week, the Packers would likely continue with Newhouse on the left side and Sherrod on the right. If Bulaga does return, he could stay at right tackle with Newhouse at left tackle, though it would also be an option to move the more experienced Bulaga to the left side.

In any event, the three offensive tackles the Packers have drafted over the past two years will be charged with protecting quarterback Aaron Rodgers from opposing defensive ends for an extended period of time.

Thus far, all that youth bookending the offensive line hasn’t given the coaching staff reason to fret.

“You just see the jump that Bryan and Marshall have made from year one to year two, and Derek is going to have to make his quicker,” McCarthy said. “This is our program, this is how we operate, and we need to continue to do a good job making sure our younger players are ready to play. This is a perfect example of it.”

McCarthy said he was “pleased” with how Newhouse and Sherrod performed against the Falcons, once they got into the flow of things.

Offensive Coordinator Joe Philbin said Sherrod, who had played mostly left guard and left tackle as a rookie in practice, needed a few plays at right tackle to get his feet wet but then functioned fine.

“There are some good shots of him getting very good separation in pass-protection, using the length he has to his advantage,” Philbin said. “I thought he was off to a good start. He was far from perfect, but I thought he was competitive and he held his own out there.”

The same can be said for Newhouse, who had to switch sides mid-game and returned to his old college position of left tackle with minimal hiccups.

“You have to give him a lot of credit,” Philbin said. “That’s not easy.

“We use the saying football is football and blocking is blocking, whether you’re on the right side or the left side, but safe to say, there are some differences. I thought he handled it well.”

Rodgers was sacked four times by the Falcons, but not all of those were the responsibility of the tackles. He threw for 396 yards, nearly topping 400 for the second straight week, with two touchdowns and no interceptions.

The Packers were down, 14-0, when Clifton left the game and the offense had to turn to Newhouse and Sherrod to hold the fort at tackle the rest of the way. The unit put together six scoring drives over its final eight possessions (four field goals, two touchdowns).

“I thought from a competitive standpoint, they didn’t make a lot of mistakes,” Philbin said. “They gave us a chance. We didn’t have to alter the offense. We didn’t have an offensive staff meeting on the phones saying, ‘OK, what are we going to do now?’

“That’s probably the best tribute you can give those guys. We stayed with our game plan, ran our offense, and those guys contributed to that.”

After overcoming 15 season-ending injuries to win the Super Bowl last year, the Packers are no strangers to shuffled lineups. That has helped them stay unbeaten this year despite a season-ending injury to safety Nick Collins, training-camp injuries to defensive end Mike Neal and outside linebacker Frank Zombo that have prevented either from playing in a game thus far, and now the more recent injuries to Bulaga and Clifton.

The mindset remains in 2011 that the next man must be ready to play, and 11 straight victories surrounding a Super Bowl title are all the proof the team needs.

“It doesn’t just kick in because the head coach gives a great speech or a couple players believe in it,” McCarthy said. “I think our experience of going through it, the plan of developing these younger players, getting them ready … they say, ‘Hey, this does work.’”

Additional coverage - Oct. 10