OXNARD, Calif. -- The Dallas Cowboys' training camp practice had been over for at least 25 minutes, maybe more, and left tackle Tyron Smith was still working on his footwork with offensive line coach Bill Callahan.
This is hardly an unusual occurrence.
Sometimes the individual sessions last a few minutes. Other times, like this one, they last considerably longer.
This is what's called paying the price to succeed in the NFL. All it costs is sweat, effort and tenacity.
Smith, taken with the ninth pick of the first round last season, starts his first preseason game at left tackle Monday night against the Oakland Raiders.
He's far from a finished product, but his performance against Oakland will provide us with some clue as to whether the lessons Callahan and pass-rusher extraordinaire DeMarcus Ware have been delivering before, during and after practice are taking hold.
Eventually, Smith will be among the NFL's best left tackles.
The only question is how long the process takes because at 6-foot-5 and 308 pounds with the long arms every classic left tackle possesses, he has the size and body type to dominate.
And he's a good enough athlete to make perimeter blocks on running and passing plays.
The product of a two-parent home that demanded work ethic and responsibility of him as a child, Smith is a mature player with the intangibles needed to thrive in the competitive world of pro football.
And he has a quality coach in Callahan, who's considered among the game's best teachers because of his ability to teach players the nuances of footwork and technique.
Still, we have absolutely no idea how Smith will handle his season at the most difficult position on the offensive line.
He played right tackle at USC and in his first season with the Cowboys. If you're right-handed, try writing with your left hand for a week and you'll get a glimpse of the switch Smith is making.
"He's still learning how to get out of his stance on that side and how to protect from that side," Cowboys coach Jason Garrett said. "He has very long arms. When he gets his hands inside guys it's hard to get away from them.
"He understands how to use them and it's an effective tool as both run- and pass-blocker."
Much of Smith's success or failure this season will depend on his footwork as he competes against some of the league's elite pass-rushers. That's because most teams put their best pass-rusher at right defensive end, allowing them to attack the quarterback's blind side.
Guys such as the New York Giants' Jason Pierre-Paul (16.5 sacks) and Philadelphia's Trent Cole (11.0) in the NFC East, and Atlanta's John Abraham (9.5) and Chicago's Julius Peppers (11.0) outside of the division.
"I'm just trying to get better and work until everything is perfect," Smith said. "Footwork has a lot to do with it.
"It's like basketball. I need to keep myself between the pass-rusher and the quarterback."
Callahan, who preaches the importance of footwork each and every day, is fond of saying feet before hands.
The footwork is the foundation for every lineman because it allows a player to generate power and force as well as be positioned correctly to strike, redirect or do whatever is required to make a block.
"Whether you're protecting against an inside move or an outside move, you really want to prevent a lineman from overextending or being off-balance or off-kilter or reaching or lunging or flailing," Callahan said. "We want their feet to be firing and moving and mirroring the defensive player, so he's in position to make the block.
"If those feet stop there's a tendency for a lineman to get off his center of gravity, and that's when the problems occur."
Smith started 16 games at right tackle last season and yielded 9.5 sacks, the same total as left tackle Doug Free, according to Stats LLC. Only six players in the NFL yielded more.
So you can expect some challenging moments at times as he adjusts to his new position, but Garrett is convinced Smith's demeanor will help him overcome any difficulties.
"He's one of the best young players I've seen at not being in awe of the situation and embracing the work that's required to be great at a position," Garrett said. "We saw that from minute one last year.
"He's a 21-year-old and he has a real mature way about him. He's mentally and physically tough -- not a lot of 21-year-olds have those traits. He's working after practice and before practice and watching tape. He's committed."
And he's good enough to lock down the position for at least a decade, which is what we should expect from a high first-round pick.