It's final four time in the Chase for the Sprint Cup championship.

Sunday's race at Martinsville Speedway is not only the seventh round in the 10-race Chase but the only short-track event in the postseason as well. Texas (Nov. 4), Phoenix (Nov. 11) and Homestead (Nov. 18) follow Martinsville.

Last weekend, Chase leaders Brad Keselowski and Jimmie Johnson survived a wild race at the newly repaved Kansas Speedway. Keselowski avoided one crash after another during the 400-mile event to finish eighth and remain the points leader. Johnson wrecked midway through the race but miraculously bounced back with a ninth-place run to keep the second spot in the Chase rankings. The point separation between the two remained at seven. Denny Hamlin finished 13th at Kansas and fell 20 markers behind.

"It's pressure time; it's go time," Johnson said. "It's all that stuff with four to go. With the points as tight as they are, we expect to be one of the cars racing for the win."

Johnson, who is seeking his sixth Sprint Cup Series championship, has yet to win a race in this year's Chase. He started the postseason with a pair of second-place finishes -- Chicagoland and New Hampshire. He placed third earlier this month at Charlotte.

"If we can get points on the 11 (Hamlin) and the 2 (Keselowski), especially the 2 at this point, that would be ideal," Johnson noted. "So we're showing up, racing hard, putting in everything we have got, which is to be expected by everybody at this point, and we'll see how things turn out."

Clint Bowyer is currently 25 points behind Keselowski, while Kasey Kahne trails by 30.

Sixth through 12th in the Chase standings are: Martin Truex Jr. (-43), Tony Stewart (-47), Jeff Gordon (-51), Matt Kenseth (-55), Kevin Harvick (-59), Greg Biffle (-62) and Dale Earnhardt Jr. (-122).

Earnhardt Jr. will return to competition at Martinsville after missing the past two races due to a concussion. He was medically cleared on Tuesday, following numerous neuropsychological evaluations, including a successful test session at the half-mile Gresham Motorsports Park in Jefferson, Ga.

The points leader after the sixth race in the Chase has gone on to win the series championship five of eight times. Last year, Stewart was 19 points behind leader Carl Edwards after the sixth Chase event, but Stewart went on to win at Martinsville, Texas and Homestead to claim the title.

Statistically, Johnson, Hamlin and Gordon have the upper hand at Martinsville. All three drivers have combined for 17 wins there, including seven in the Chase (2004-10).

In 21 races at Martinsville, Johnson has an average finish of 5.8, which is tops among active drivers. He has won six times at this track but has not been to victory lane there since March 2009. He finished second at Martinsville one year ago and 12th there in April.

Hamlin has an average finish of 6.4 in 14 races at Martinsville. He has four victories there, including three in a row from 2009-10. Hamlin placed fifth at Martinsville in last year's Chase race and then sixth there earlier this year.

"The spring race is the one race where we did just not run well," Hamlin said. "We had some setup issues that we found in the car afterwards, and some mistakes that we made with our setup. Basically, putting the wrong pieces in the wrong places. So, that is hopefully why we ran so bad in the spring where we finished decent but not great. Hopefully, that's rectified. Honestly, we look forward to going back, especially as good as our short track program has been in the last few (races)."

Gordon leads all active drivers with seven wins at Martinsville, but the four- time series champion has not posted a victory there since Oct. 2005. His average finish in 39 starts at this track is not too shabby -- 7.1.

"Martinsville is just that kind of place where you get into a rhythm," Gordon said. "And it's important when you get into traffic to maintain that rhythm or get back into it as fast as you possibly can. No other track demands the kind of rhythm needed at Martinsville."

For Keselowski, Martinsville could be a roadblock in his quest for the Sprint Cup title. He has competed there just five times, scoring a pair of top-10 finishes. He placed ninth at Martinsville in the spring.

"Martinsville is just one of those tracks where it seems like there are numerous variables that we've struggled with, and I don't think they're our fault," Keselowski said. "When I look at last year, I think we were running fifth or sixth in the fall and just got caught up in a wreck on a late-race restart caused by somebody who retaliated on the track."

Chevrolet can mathematically clinch its 10th consecutive and 36th overall manufacturers' championship in NASCAR's premier series this weekend at Martinsville. The auto maker presently holds a 22-point lead. Chevrolet will guarantee a clinch if one of its drivers finishes second or better there.

Forty-five teams are on the preliminary entry list for the Tums Fast Relief 500.

Series: NASCAR Sprint Cup. Date: Sunday, Oct. 28. Race: Tums Fast Relief 500. Site: Martinsville Speedway. Track: 0.526-mile oval. Start time: 2:00 p.m.(ET). Laps: 500. Miles: 263. 2011 Winner: Tony Stewart. Television: ESPN. Radio: Motor Racing Network (MRN)/SIRIUS NASCAR Radio.