DOVER, Del. — Four-time NASCAR champion Jeff Gordon said Friday he will have to retire if he continues to suffer the same, excruciating back pain that he did before last weekend’s Coca-Cola 600.

The 42-year-old Gordon is in no hurry to slow down. But he said he hopes he has found some solutions to the back woes that nearly forced him out of NASCAR’s longest race. Gordon cut short his practice runs last week because of back spasms and there was some concern whether or not he would be able to race.

Regan Smith was on standby and Gordon needed treatment after the practice session. But he wound up in his familiar seat behind the wheel of the No. 24 and finished seventh, his ninth top-10 finish in 12 races this season.

Gordon knows consistent, shooting pain like he suffered at Charlotte Motor Speedway could drive him toward an early retirement.

“I can tell you, if that happens many more times, I won’t have a choice,” Gordon said Friday at Dover Motor Speedway.

Keselowski wins Dover pole

DOVER, Del. — Brad Keselowski is getting used to racing out front, turning a track-record lap of 164.444 mph to win the pole at Dover International Speedway.

Keselowski won his second pole of the season Friday on the mile track and fifth of his career. He also has six starts from second this season, making him one of the top front-row performers in NASCAR.

“It’s been a good year for qualifying,” Keselowski said, “And I would say most years, that has not been the case.”

Keselowski and his Team Penske teammate Joey Logano have figured out fast qualifying in their Fords. Kyle Busch starts second, and Logano, eight-time Dover winner Jimmie Johnson and rookie Kyle Larson round out the top five for Sunday’s race.

Series points leader Jeff Gordon was sixth, followed by Denny Hamlin, Kevin Harvick, Brian Vickers and Clint Bowyer. Bowyer turned 35 on Friday.

Kyle Busch wins Truck race

DOVER, Del. — Kyle Busch made it 4 for 4 in the Truck Series, dominating again to win at Dover International Speedway.

Busch was again the class of the field Friday and now has a checkered flag at Dover to go along with ones from Daytona, Kansas and Charlotte. He has 39 series victories.

Busch won from the pole for the third time.

Busch does not a run a full season. He has won every race he entered. He can make it a tripleheader sweep with a win in Saturday’s Nationwide race and Sunday’s Cup race.

Ryan Blaney was second, and Johnny Sauter, Brandon Jones and Joey Coulter rounded out the top five. Only seven trucks finished on the lead lap

IndyCar drivers in for change

DETROIT — IndyCar drivers are in for quite a shift.

The Detroit Grand Prix will feature racing at speeds up to 165 mph on bumpy streets with 13 turns on an island between the United States and Canada.

Less than a week ago, many of those same drivers were going about 70 mph faster on a smooth surface around an oval at the Indianapolis 500.

Simon Pagenaud and Mike Conway hope the Detroit Grand Prix is a lot like it was in 2013. Pagenaud and Conway each won once last year on Belle Isle’s street circuit. And they had the fastest cars in two practice sessions Friday.

Pagenaud turned a lap of 108.950 mph, just slightly faster than Conway..