The Cowboys are clearly a team in transition. You don't have to look further than the offensive line to realize that. Five of Emmitt Smith's eight blockers have four years or less experience, four have two years or less.

In most circumstances, it would be ideal to have a 33-year-old back with the mind and body of Smith. At 33, Smith is still averaging 4.2 yards a carry. Few backs in the history of this league execute those downhill running plays as well as Smith.

Smith is a perfect veteran starting back for a team with a young offensive line. The problem is that he isn't the ideal back for the current Dallas Cowboys offense. His knowledge of the running game doesn't necessarily fit with the changes.

At the Super Bowl, I had the misfortune of breaking the news to Smith that the Cowboys were going a different direction with their offense. They had fired their longtime offensive line coach Hudson Houck and their running back coach Clarence Shelmon. Smith was stunned. Like many backs who have been around him, Shelmon is considered one of the best at his position. Why? He tries to adjust the running game to fit the talents of the backs.

Jerry Jones quickly hired Bruce Coslett to be the offensive coordinator. For a team grooming young quarterbacks Quincy Carter and Chad Hutchinson, the move was ideal. Coslett works well with young quarterbacks. He brings the West Coast offense, which may take time for the quarterbacks to learn, but once the quarterbacks get the hang of that offense, they can get rid of the ball quickly and avoid hits.

The problem with the West Coast offense is that it doesn't fit the style of the 33-year-old running. "I'm not a West Coast back," Smith said. But great backs adjust, and Smith is one of the greatest in the history of the league. So while he adjusted his game to make the most of the opportunities, the problem is what is happening up front betrays Smith's best style.

The Cowboys offensive line is adjusting to a zone-blocking scheme for the guards and the center. Center Andre Gurode is a rookie and he's fighting off knee problems that forced him to miss two games. Zone blocking protects the center.

Pro Bowl guard Larry Allen hated the zone blocking. So he asked to be moved to right tackle so he gets to use more of his man-on-man skills. Allen is a potential Hall-of-Famer. He manhandles defenders. The problem this year is that he has an ankle injury that has kept him off the field and severely limited his game. He went to tackle and struggled because of the ankle.

The Cowboys moved him back to guard because of his diminished mobility. Last week, he was inactive, and the Cowboys had a very young line.

Smith's problem running behind this line is that he can't be at his best. Smith's best running plays involve taking a handoff, finding a hole and making the one defender in the hole miss. His strength has always been hitting the hole going one direction and making the quick cutback move away from the defender the other way.

Zone blocking chips away at those cutback lanes.

The other problem for Smith is he isn't getting the carries. Smith has always been the workhorse in the Cowboys offense. The more action he gets the better he runs. The more that an offensive line can wear down a defensive line, the better Smith is by the fourth quarter.

Smith is averaging 15 carries a game. He's had only one 22-carry game, which was last week against the Cardinals. Part of the problems is that the erratic young Cowboys haven't had the lead much this season. Only 16 of Smith's carries came with the Cowboys ahead.

For years, the Cowboys had the lead and Smith took the air out of comebacks because he could run downhill and make it tough for the opposing offense to get back on the field. Smith has only 18 carries in the fourth quarter in his first seven games. In the past, he'd have those numbers in two games.

Again, teams have the right to change philosophies. Jerry Jones wanted to find a system that develops quarterbacks, and Coslett's West Coast schemes may take time to learn, but they usually create good quarterbacks. The future of the Cowboys involves Carter and Hutchinson, not Emmitt Smith.

But this system doesn't allow Smith to help young quarterbacks or a young offensive line as it did in the past. A back such as Smith can get the 20-to-25 carries a game and allow the quarterback to handle less of the load. That's exactly the formula that is being used in San Diego. LaDainian Tomlinson gets between 25-to-39 carries a game. Drew Brees doesn't bear the pressure of the offense.

Maybe the switch to Hutchinson will cause the Cowboys to use Smith more, but don't count on it.

On Sunday, they enter the unknown with Hutchinson at quarterback. Hutchinson could throw interceptions. He could fumble snaps. Being so inexperienced, he will make mistakes that will take the flow and rhythm out of the offense.

What will be interesting is to see what happens after Smith breaks Walter Payton's record. Will Smith be phased out as the season progresses and Troy Hambrick gets more action?

For years, Smith drove the Cowboys offense. Nowadays, he's just a passenger along for the ride.

John Clayton is a senior writer for ESPN.com.