Tony Stewart will not race Sunday at Watkins Glen after he struck and killed a driver in a dirt track race in upstate New York Saturday night. Regan Smith will replace him.

Stewart-Haas Competition Director Greg Zipadelli announced the decision Sunday morning. Previously, Zipadelli had characterized the team's preparations as "business as usual."

"We talked last night and then realizing going through the night – give Tony some time to sleep on it – and met with him this morning and he feels strongly that this is the right thing to do," Zipadelli said. "We at SHR support it and agree with it. Like I said, it's a difficult time for both parties."

"There's not a lot we can do. The only thing we can do is do what we feel is right and this is what we feel is right and supporting Tony in it."

Stewart hit Kevin Ward after Ward had exited his vehicle during a race at Canandaigua Motorsports Park Saturday night. After the two had a close racing incident in turn two, Ward exited his car and walked down the track to confront Stewart and was clipped by Stewart's car.

The incident was captured on video, and can be viewed here (Warning: it’s disturbing to watch).

Shortly after the green flag flew in Sunday's race, Stewart issued a statement.

"There aren’t words to describe the sadness I feel about the accident that took the life of Kevin Ward Jr." Stewart said "It’s a very emotional time for all involved, and it is the reason I’ve decided not to participate in today’s race at Watkins Glen. My thoughts and prayers are with his family, friends and everyone affected by this tragedy.”

NASCAR released a statement that said it supported Stewart's decision.

Sunday afternoon, the Ontario County Sheriff's Department held a press conference and Sheriff Phillip Povero said his department had learned nothing to suggest that criminal activity was involved.

Zipadelli said the team hadn't given any thought to the impact the decision would have on Stewart's Chase chances. With five races to go before the Chase, Stewart was likely needing a win to advance to the Chase. Watkins Glen is historically one of his best tracks. He's won there five times.

"No, honestly this is the furthest thing from our minds right now. The well-being of Kevin's family and Tony and the people at our company. That's something when we get home on Monday we will have to look at and evaluate and go through that and make decisions. Today is all about doing what we can today to get through today and do it the best we can as a group and try to do it in the right way. So we haven't even crossed that bridge yet."

NASCAR has a provision built into the new Chase format that gives the sanctioning body leeway to allow drivers who have attempted to qualify for a race the ability to stay Chase eligible despite missing a race. Earlier this season, Denny Hamlin missed a race at California because of an eye issue and NASCAR said Hamlin was still eligible for the Chase.

It's the second-straight race at Watkins Glen that Stewart has missed. He missed last year's race after he broke his leg in a sprint car accident in Iowa. Max Papis replaced him in 2013. Smith drives full time for JR Motorsports in the Nationwide Series. He has one career Sprint Cup Series win.

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Nick Bromberg is the editor of From The Marbles on Yahoo Sports. Have a tip? Email him at nickbromberg@yahoo.com or follow him on Twitter!

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