Regan Smith is no stranger to stepping in for a Monster Energy NASCAR Cup Series driver.

Smith - who has filled in for Dale Earnhardt Jr., Jimmie Johnson, Tony Stewart, Kurt Busch and Kyle Larson, among others - will drive Aric Almirola's No. 43 Smithfield Ford in Saturday's Monster Energy Open at Charlotte Motor Speedway.

Almirola suffered a back fracture in a crash last week at Kansas Speedway and is expected to be out of the car for two to three months. Currently a driver for Ricky Benton Racing in the NASCAR Camping World Truck Series, Smith said his goal is to put Richard Petty Motorsports' No. 43 car in the Monster Energy All-Star Race by winning one of the Open's three stages. His tenure in the No. 43 remains to be seen beyond this weekend.

Smith has already learned one valuable lesson.

"I've learned I have a hell of a polo shirt collection at this point," Smith said Friday. "I don't know if there's any crew members in the garage who have been with more teams than I have."

Smith's first high-profile Monster Energy NASCAR Cup Series fill-in job came at Charlotte Motor Speedway in October 2012, when he piloted Earnhardt's No. 88 Chevrolet for two races after Earnhardt sustained a concussion.

"That one was a little more last-minute," Smith said. "Nobody knew (Earnhardt) was hurt (before race weekend). I was mentally prepared to hop in a different race car. When you look at (Almirola's) situation, there was a little bit of time. You could go to the shop. You could sit in the car. You can adjust things. It's not quite as on-the-fly as (Earnhardt's) was. You can prepare for what the weekend's going to look like."

Driving for Richard Petty, NASCAR's all-time winningest driver, is a new experience for the veteran pilot.

"That's pretty awesome," Smith said. "When I looked back late last season I didn't know what I'd be doing this season. I was thinking I'd get an opportunity in a Cup car again but when this all shook down, I thought, 'Man, that's pretty cool. That's The King's car.' Because me and Aric are friends I guess I have more of an emotional investment in wanting to do well for him and for this team."