Another win for Dale Earnhardt Jr. will make him a true Chase force

Can he do it again? That's the big question in NASCAR as the Sprint Cup series heads Sunday to Michigan International Speedway, where in June Dale Earnhardt

Crew chief Steve Letarte helped Dale Earnhardt earn his first win in four seasons in Michigan last June :: John Harrelson/Getty Images

Can he do it again?

That's the big question in NASCAR as the Sprint Cup series heads Sunday to Michigan International Speedway, where in June Dale Earnhardt Jr. -- NASCAR's most popular driver nine seasons running -- won for the first time in four years. Since then Earnhardt has had a respectable three top-five finishes in seven starts, but he's fallen from second to fourth in the standings. Make no mistake, Michigan is going to be a measuring-stick race for the No. 88 team; if Earnhardt is going to be a force in the Chase, he needs to perform well at his best tracks, and that includes Michigan.

"I feel like when we go back to Michigan we should have a really good shot at winning again," Earnhardt said recently. "We seemed to have figured some things out there. I can't wait."

Throughout 2012 Earnhardt has shown an enthusiasm we haven't seen in recent years; he simply can't wait to get to the track. Much of the credit can be given to his crew chief of two years Steve Letarte, who revitalized Earnhardt's career. For example, Earnhardt used to dread the team de-brief sessions after practice. He wouldn't be engaged intellectually and would count down the minutes until he'd be excused so he could go hang out in his motor coach in the driver's lot. Well, now he relishes his time with Letarte in the debriefs, and usually he lingers in the team hauler -- the track headquarters for Letarte and his engineers on the 88 team -- long after the debrief is over. It's only a little thing, but Earnhardt's newfound professionalism has translated into more speed on Sundays.

"Steve and I genuinely like each other and enjoy each other's company," Earnhardt says. "Our chemistry is just right. It's a night and day difference for me."

And that's why I think Earnhardt will be a threat this autumn to win his first Cup championship. He's capable of running strong on every Chase track, but he needs to improve his consistency on the intermediate-length tracks that measure 1.5- and two-miles. (Five of the ten Chase races take place at these venues.) In June Earnhardt led 95 of the 200 laps at Michigan, a flat, two-mile oval; he may not be as dominant on Sunday, but he's my pick to reach Victory Lane.

Here are four other drivers to watch when the green flag waves in the Irish Hills of Michigan:

1.Jimmie Johnson

Ever since he won at Indy on July 29th, Johnson has consistently flashed more speed than any other driver. The garage is still focused on the rear bumper of Johnson's No. 48 Chevy, which has been pitched at a higher angle than usual and seems to give Johnson the ability to plow through the corners faster than the competition.

Michigan is a flat track like Indy (where Johnson led 99 of 160 laps) and Pocono (where on Aug. 5 Johnson led 44 of 98 laps), so Johnson clearly has had mechanical edge over the field at these venues. Setup secrets eventually "bleed out" in the garage, but it normally takes time. Has any crew chief or engineer figured out what has given Johnson this edge? Well, if no one has, then Johnson could run away from the other drivers on Sunday. Stay tuned.

2. Kyle Busch

Busch was in prime position to take his second checkered flag of 2012 last Sunday at Watkins Glen International, but while in the lead on the final lap he ran over some oil, made contact with Brad Keselowski and was passed by several cars. Now Busch, who is currently 14th in the standings, likely needs to win one of the final four regular season races to advance to the Chase.

Busch won this race last year and has two top-three finishes in his last three starts at Michigan. We're rapidly approaching now-or-never time for Busch, so expect him to be very fast -- and very aggressive -- on Sunday.

3. Marcos Ambrose

After winning his first race of the season on Sunday at Watkins Glen, Ambrose suddenly is a factor in the wildcard hunt. He's now 17th in the standings and could grab one of the two wildcard spots if he reaches Victory Lane one more time in the regular season.

Ambrose's best chance to do that likely will be at Michigan, where in June he sat on the pole, led 15 laps, and finished ninth. Ambrose is one of the most pleasant personalities in NASCAR, and he could inject a freshness into the Chase that the sport could use. Yes, he's a long shot to make the playoffs, but if you're a fan of underdogs, you should be in Ambrose's corner on Sunday.

4. Carl Edwards

Edwards is in danger of winning the Most Disappointing Driver Award for 2012. A year after finishing second to Tony Stewart in the Chase -- and holding the points lead for the majority of the season -- Edwards has been a non-factor. He dealt with a crew chief change (Bob Osborne left his position atop the No. 99 pit box for health reasons in June and was replaced by Chad Norris) and is now 12th in the standings with zero wins.

Edwards only has one top-10 finish in his last four starts; yet he could surprise on Sunday. Statistically, Michigan is Edwards' second-best track on the circuit -- in 16 career starts at the two-mile venue his average finish is 8.4 (he's only better at Homestead, where his average is 6.2). What's more, his team owner, Jack Roush, considers Michigan to be one of the most important races of the season, because he'll be hosting executives from the nearby Ford headquarters. So you can be sure that an ample amount of resources will have been poured into Edwards' No. 99 Ford that he'll run on Sunday.

But I think this event will belong to Earnhardt. No driver has swept both Michigan races since Bobby Labonte in 1995, but it says here that streak ends on Sunday