Mark Martin sounds determined to make Sunday’s race his last in a major NASCAR series. Ken Schrader reportedly is going to compete in his final Cup event.

Jeff Burton is ending his status as a full-time Cup driver, too.

In a sport where drivers often compete well into their 40s and 50s — most respectably enough that teams prefer to go with experience rather than the unknown — the Ford EcoBoost 400 could signify an end of an era of sorts.

The drivers approach the end in different ways.

“You don’t want to just say, ‘If that’s it, it’s OK,’” Labonte said last week at Phoenix. “It’s not OK. But, you know, it’s also reality, too. You don’t know. I don’t have a crystal ball and I can’t tell.

“If it was (my last race), you’d be disappointed for a while.”

For Martin, he seems ready to move on.

“Father Time does take its toll on every single sense that you have,” Martin said. “Your hand-eye coordination, everything is affected as you get older. At some point in time, that decline becomes a detriment to you.

“You can work as hard as you want and you can maybe run good, but you’re fighting Father Time, and that’s different for anyone.”

The 54-year-old Martin has 40 Cup wins in 881 starts. The 58-year-old Schrader has four Cup wins in 782 starts and is still active racing short tracks.

The 49-year-old Labonte has 21 career wins in 718 starts. The 46-year-old Burton has 21 career Cup wins in 690 starts.

Of the group, only Burton has run the entire season and he is being squeezed out at Richard Childress Racing with one year left on his contract. He is 19th in the standings with six top-10s but a 184-race winless streak. He plans to run a partial schedule next season but has not announced the team.

“What happens is the older you get the more other things matter,” Burton said. “Racing still means a lot to me, but for me to sit here today and say it means the same thing to me that it meant when I didn’t have a daughter getting ready to go to college, a son that is racing, those things they do play a role.

“The schedule is harder today than it’s ever been. … You are gone more today. It boils down to desire. If you have talent, I don’t think talent goes away. Certainly eyesight changes, those kinds of things change, but we can fix that. But talent doesn’t change; it’s more the passion that you are willing to bring to it.”

Martin has competed in 27 of the 35 races this year with one top-five and five top-10s. His average finish is 20.1. It appears some of his passion has been sapped by his lack of performance.

“I can still drive a racecar pretty fast, but I’m not the driver I was at my peak,” Martin said. “I know it. … I’m not saying I can’t run good, but I know that I can feel it in everything I do, every time I get up and walk across the room, I can tell that I’m not 35.

“And anybody that says they can’t, I don’t know. I’d like to be sipping off some of their juice — you know what I’m saying? Because I can tell.”

Labonte is not ready to give up but is looking for a 2014 ride as he is being replaced by AJ Allmendinger at JTG Daugherty Racing. He has a best finish of 15th this year in 28 starts.

“We’re not 35 trying to do it or 25 trying to do it either,” Labonte said. “It’s just kind of the way it is.”


HOW KENSETH, HARVICK CAN WIN


Jimmie Johnson is really racing only two drivers this weekend: Matt Kenseth and Kevin Harvick.

For Johnson to lose the Sprint Cup championship to either of those two drivers, he most likely will need to have a problem on the track.

That doesn’t mean there’s not stress for the five-time champion.

“It's so easy to throw these things away,” Johnson crew chief Chad Knaus said. “We see it time and time again. There's things that you cannot control, there's things that you can control, and we've got to make sure that we can control what is in our ability and put our best foot forward.

“If we don't, if we let something slip, it could be a big problem.”

Johnson leads Kenseth by 28 points and Harvick by 34. Johnson wins the championship if he finishes 23rd or better, 24th or better if he leads a lap or 25th or better if he leads the most laps.

If he struggles or has a problem and finishes worse than those spots, Kenseth and Harvick have a chance. Kenseth, with seven wins, owns the tiebreaker over Johnson (six wins) and Harvick (four wins). Johnson owns the tiebreaker over Harvick.

Each position on the track is worth one point with drivers who lead a lap getting one bonus point apiece, the driver who leads the most laps getting another bonus point and the winning driver earning an additional three bonus points. If there is a tie for most laps led, each of those drivers earns a bonus point.

So if none of the three drivers wins the race, Kenseth must beat Johnson by 28 spots and not lose to Harvick by seven spots, give or take two spots depending on if either leads a lap or the most laps. Harvick must beat Kenseth by seven spots and Johnson by 35.


DILLON LEADS HORNISH


Austin Dillon has an eight-point lead over Sam Hornish Jr. for the Nationwide Series championship.

With one win for Hornish this year and Dillon having none, Hornish owns the tiebreaker.

If Hornish wins the race and leads the most laps, Dillon still wins the title if he finishes third, fourth if he leads a lap or fifth if he leads the most laps. If Hornish wins the race but does not lead the most laps, then Dillon just needs to finish fourth or fifth.

If Hornish doesn’t win, then he must beat Dillon by eight spots, give or take one or two spots depending on whether either of them leads a lap and/or leads the most laps.


CRAFTON SET TO WIN TRUCK TITLE


Matt Crafton leads the Camping World Truck Series race by 46 points over Ty Dillon.

Because there are only 36 trucks that start a race, Crafton will clinch the title just by starting the race. If he does not start the race, Dillon would have to win the race to win the championship.

Contributors: Bob Pockrass, The Sporting News staff