Richard Buck is relishing his new opportunity as the managing director of NASCAR's Sprint Cup Series.

But first, he must complete his current role as vice president of the International Motor Sports Association through the sanctioning body's kickoff event -- the Rolex 24 at Daytona on Jan. 25-26. Buck then says he'll be ready to tackle his new challenge.

"I feel very fortunate to be given this opportunity -- and I'm ready," Buck told FOXSports.com. "I'm ready to get going. I still have to finish my responsibilities with the new IMSA -- and the Tudor (United SportsCar Championship) series. I'm just looking to get after it.

"I have to get up to speed in all the stuff that's going on, but obviously my plate is full with the merging of ALMS and GRAND-AM. That's my responsibility, so I want to fulfill that first.”

Buck replaces John Darby, who has overseen the Sprint Cup Series for the past 12 years and will remain on as managing director, competition. Buck, along with Nationwide Series director Wayne Auton and Camping World Truck Series chief Chad Little, will report to NASCAR vice president of competition Robin Pemberton.

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John Darby has overseen the Sprint Cup Series for the past 12 years.

NASCAR president Mike Helton says Buck's promotion is part of "the evolution" of the competition department.

"Richard will maintain his role at IMSA through the 24-hour race and then will immediately get with John Darby and, by under John's wing, to get him up and winning as our new Sprint Cup Series managing director. John will stay with us ... and be working on the integration of a lot of the new inspection and rule making and part approval process with Robin Pemberton and Gene Stefanyshyn (vice president, innovation and racing development).

"Over time, John may end up being or will end up being less at the racetrack, more back at home at the R&D Center as we move a lot of our competition elements based out of there, as opposed to being some of the traditional ways of doing it at the racetrack."

Buck brings a wealth of motorsports experience to the position. He came up through open-wheel ranks as a crew chief, team manager and director of operations, and led teams to three Indianapolis 500 victories during his tenure in CART. Prior to joining NASCAR in 2005, the 51-year-old Phoenix native worked with teams from the top three divisions. While one of Darby's greatest strengths is his relationship with the competitors, Buck believes that's one of the traits that will make him equally effective.

"That's one of the most important things is to be able to grow that and make new relationships," Buck said. "I've had the opportunity to so-call chew the dirt with some of these guys -- some of the same dirt as Tony Stewart. I came from sprint cars, as well, World of Outlaws, open wheel, so those are the kind of guys I relate to.

"There are a lot of up-and-coming stars that have come from the K&N Pro Series and the touring series that are now here -- Joey Logano, Trevor Bayne, Kyle Larson. So, I already have relationships started over there and am looking to build and having a real strong relationship with everybody in the garage area, owners included."