Stewart loses Pocono pole

During the first practice session of the day, Stewart lost control of his car at the exit of Turn 2 and slid towards the inside grass, where the bottom of his #14 Chevrolet hit the ground, causing considerable damage to the nose section.

"I went off into the grass but I hit the right front of the splitter with I guess one of the access roads or something and ripped the whole nose off it," said Stewart, who was set to start from the pole for the first time since qualifying got rained out at Bristol in 2006.

Despite his incident in the first session, Stewart's second timed lap of the day had allowed him to finish third in the 45-minute practice, which was dominated by reigning champion Jimmie Johnson.

Two-time Sprint Cup champion Stewart switched to his back-up car for the second practice, which he finished in sixth place 0.165 seconds off Denny Hamlin's benchmark. According to NASCAR rules, the change forces him to start from the back of the field.

Although his times with his primary car were better than with his back-up, track conditions made for a slower second session and Stewart confirmed he had a better feel with his spare, which he already raced this year at Las Vegas.

"I feel like it's better than the primary car," Stewart said. "I was happier with that car than I was the first one. If I'd known the second one was going to be so good, I would have crashed the first one the first lap out."

Newman's team-mate Ryan Newman was second fastest in both practice session, as Stewart's team continues to impress in its debut season.

Another driver starting form the back of the field will be Robby Gordon, who did not drive his car in Saturday's practice as he was competing in the Baja 500 in Mexico. Travis Kvapil drove his car but Gordon will be back at Pocono for Sunday's race.