Sam Hornish Jr. was sitting in a television studio in Charlotte, N.C., on Saturday afternoon, giving his prediction on who would win that night's race at Daytona International Speedway, when the cell phone in his pocket began to vibrate. Appearing on a live Speed network program, he didn't have the opportunity to answer it. He checked his messages after the program ended and before he was supposed to tape another segment to air the next day.

"I said, 'Hold on, I have to make a call real quick,'" Hornish said. "And then I was like, 'Nope, I can't.'"

Thus began the whirlwind that landed the regular Penske Racing Nationwide Series driver in the seat of the No. 22 Sprint Cup car for Daytona's summertime 400 miler. The Penske team was informed Saturday afternoon that AJ Allmendinger was suspended temporarily for failing a random drug test conducted the previous weekend in Kentucky, and it needed another driver for the No. 22 on short notice. The natural was Hornish, a former Indianapolis 500 champion with 110 Cup starts. The problem was getting him to Daytona in time to start the race.

Hornish finished 10th in Friday night's Nationwide race at Daytona, after which he returned home. His phone began to buzz during the first segment of "Speed Center," which aired from 4 to 4:30 p.m. Saturday. When he finally checked his phone, he found a message from Penske operations director Mike Nelson.

"They said, 'We think we might need you [Saturday night],'" Hornish said. "I said, 'OK.'"

Hornish called Walt Czarnecki, Penske's executive vice president, who informed the driver that his services would indeed be required. A member of Hornish's Nationwide crew was dispatched to pick up a firesuit while the driver headed to the airport.

The drive took 20 minutes. Once there, Hornish said he waited another 45 minutes for Penske's private plane to get him. In the air, he changed into his firesuit -- the Alliance Truck Parts version from his Nationwide team -- and tried to hydrate the best he could.

"We sat there and had no idea what was going to happen from the time that I left Charlotte to when I got to Daytona," he said. "All the way up until the plane took off, we didn't know if we were going to make the race in time. I said that I would tell the pilot to fly faster, but I'm pretty sure that he was going to have the throttle pinned the whole way down."

It was going to be close. The Penske team had enlisted Kenny Wallace as an emergency standby. "It was one of those deals where we flew in, I half expected to see race cars going around the track," Hornish said.

Instead, he touched down in Daytona, where the airport is conveniently adjacent to the race track, to find a police escort waiting for him. "It's kind of a weird thing when you land in an airplane and you see cop lights that are out there for you," he said.

At about 7:30 p.m., just as the invocation was being issued, a black SUV -- led by a pair of police motorcycles with blue lights flashing -- sped through a back gate of the garage area, whisking Hornish to pit road. The No. 22 team quickly put Hornish's seat and steering wheel in the car while he thanked Wallace for being on standby. Penske teammate Brad Keselowski came over and spoke to Hornish shortly before the engines fired, and over the radio, crew chief Todd Gordon thanked his driver for all he had been through to make the race.

"Appreciate you helping out here, Sam," Gordon said. "... Appreciate the effort you took to get here."

"A little bit different day for me," Hornish responded, "doing TV and then getting in an airplane and driving a race car. I'll try to be as smooth and smart as I can be, try to make sure that we have something for the end and get you guys as many points as we can."

Hornish had to start at the rear because of the driver change, but by Lap 34, he had worked his way into the top 20. He fell back some after a pit stop, then on Lap 81 wound up in the backstretch wall after a tire went down on him, shredding the quarterpanel in the process. The team lost 10 laps in the garage making repairs, and Hornish finished a disappointing 33rd place.

"We had a good car," he said. "We were just trying to be smart and bide our time, and we ended up cutting down a tire, and that basically ended our race. That's unfortunate because I feel like these restrictor-plate races give you opportunities to go out there and make something happen at the end. We just barely made it past halfway when the tire let go on us and ripped the quarter off."

Although the No. 22 team made changes in the car to accommodate Hornish, the race was something of an arduous effort. Hornish said his headrest was a little off, his steering wheel was a little off and he didn't have enough advance notice to properly hydrate or fuel himself for a Cup race on a very hot Florida day.

"All in all, I couldn't have asked for much more in that short of a time period," he said. "... But I knew I was going to be off a little bit because I wasn't able to take all the steps you would normally take to be in one of these hot races."

NASCAR announced Saturday afternoon that Allmendinger's "A" sample from Kentucky has tested positive for an undisclosed banned substance. The driver had 72 hours to request that his "B" sample also be tested. If that also fails, or if Allmendinger declines to have it tested, he would be suspended indefinitely until undergoing further examination or treatment.

Saturday night, there were no indications of who would be in the No. 22 car next weekend at New Hampshire. If it's Hornish, it can't be a more challenging situation than the whirlwind he faced at Daytona.

"I don't know if I should say I'm happy to be here or not," Hornish said. "It's definitely not the kind of race I wanted to have. I got to do a lot of things I've never gotten to do before -- put a race suit on in an airplane, get an escort in to the track. ... But all in all, thankful for the opportunity to come down here and run."