FOXBOROUGH -- One came from Brantford, Ontario, and worked construction for two years before attending college. The other grew up on a 10,000-acre cattle ranch in Catheys Valley, Calif., and had dreams of being a professional steer roper.
So it's no surprise that Nick Kaczur (third round) and Logan Mankins (first round) didn't know each other when the Patriots drafted them last April.
But now? All it took was eight months, the last three of which they've lined up in lockstep on the left side of the Patriots' offensive line, to realize they have much in common.
''We're almost spitting images of each other, just our personalities and the way we go about things," said Kaczur, the raspy-voiced left tackle.
Said Mankins, the left guard: ''Both quiet guys who just go about our business and don't worry about anyone else."
Kaczur has been a surprise starter for 11 games, stepping in when veteran Matt Light -- who had started 63 straight games at left tackle -- broke his right fibula Sept. 25 against the Steelers. Mankins had been working with the first string from the first day of practice, taking Joe Andruzzi's old spot at left guard. He's one of eight Patriots to start all 16 games this season.
It's rare to see two rookies starting on the offensive line, a spot where at least one year of seasoning is recommended because of the physicality of the game and complex blocking schemes.
So rare, in fact, that this marks the first time in Bill Belichick's head coaching career that it's happened, and only the second time overall.
Belichick said the only comparable season was with the Giants in 1988, with first-round choice Eric Moore (10 starts) and second-rounder Jumbo Elliott (five starts).
The Kaczur-Mankins pairing faces its next challenge in Saturday night's playoff game against the Jaguars. The Jacksonville defensive line -- ends Paul Spicer and Reggie Hayward; tackles Marcus Stroud and John Henderson -- is considered one of the strongest units in the league. The Jaguars' 47 sacks rank third in the NFL (first based on opponents' pass attempts).
Chalk it up as the latest in a long line of welcome-to-the-NFL tests.
''They've played against a lot of good guys this year and that hasn't really rattled them," said Belichick. ''Some plays are better than others, they've gotten beat, but it isn't like they completely unravel when that happens."
Kaczur, the blind-side protector of quarterback Tom Brady, said each opponent brings a different challenge. One week you get speed rushers such as Buffalo's Aaron Schobel, Indianapolis's Dwight Freeney, or Kansas City's Jared Allen. The next week it might be a player who combines speed and power, such as the Jets' John Abraham.
Mankins's résumé lists top-notch opponents such as Oakland's Warren Sapp, Carolina's Brentson Buckner, Atlanta's Rod Coleman, Buffalo's Sam Adams, and Indianapolis's Corey Simon, among others.
''All these guys speak for themselves, they've already made a name for themselves," Kaczur said.
Kaczur has been flagged for just two false-start penalties and one holding infraction, while Mankins -- who received one vote in the Associated Press Offensive Rookie of the Year voting yesterday -- has been called for three holds and two false starts. The line has surrendered only 28 sacks in 564 pass attempts, a stat helped by Brady's quick release and pocket presence, but also an indication of the unit's stinginess.
Having two rookies starting on the line has surprised at least one NFL coach.
''I always say offensive line is more of a developmental position than some others because of all the things that can happen to you very quickly right in front of you," said Dolphins coach Nick Saban. ''You have to determine who you need to block, how you need to technique-wise block them, and then know the multiples and teamwork that it takes with the guy next to you. Usually that takes a little time to develop, and that is pretty astonishing about what those two guys have done.
''They've played really well and haven't had a great deal of time to go through that development. They've had a lot of on-the-job training."
Belichick has been pleased with the way Mankins and Kaczur have responded, in games and practices.
''I think both have a good level of maturity, they're serious about their job, they work hard, and they don't get rattled," he said. ''[Offensive line coach] Dante [Scarnecchia] yells at them. I yell at them. They seem to be able to handle that and take it in stride."
Belichick said the two have important traits that the Patriots try to identify in all linemen.
''A lot of guys have ability, but without the intelligence, maturity, and consistency -- as well as discipline and toughness -- it's hard for that ability to manifest itself," he said.
It helps that at 26, Kaczur is older than most rookies, a result of working two years of construction before enrolling at the University of Toledo.
Another factor in Kaczur's favor was that his line coach at Toledo, Mike Devlin, was a seven-year NFL veteran and coaches with a Scarnecchia-like bite and attention to detail.
Meanwhile, the 23-year-old Mankins developed his mental toughness on the cattle ranch on which he grew up. On the football field, he learned under the tutelage of former Belichick assistant Pat Hill, the head coach at Fresno State.
''Both of us want to be the best players we can be and we work hard to get better," said Mankins. ''We expect to make the blocks and do what we're supposed to do, whether we're rookies or 10-year veterans."
Mankins said the two often speak about the unique football experience they're living together, although they don't spend much time together away from the stadium. Mankins is often busy with his kids, while Kaczur is single.
Yet that doesn't mean they haven't established a strong football bond.
''Me and him together, playing side by side at the same time, you're definitely going to develop a relationship," Kaczur said. ''We're both quiet. We don't say much. We just want to go out and get the job done."
To this point, it's been a job well done.