Jeff Burton was behind the wheel of the Mobil1/Bass Pro Shops Chevrolet again at Bristol Motor Speedway last weekend. (Rainier Ehrhardt / Getty Images)

Tony Stewart has not driven in a NASCAR race since his sprint-car struck and killed a driver during a dirt-track race in early August and, as long as an investigation into the death of Kevin Ward Jr. continues, that isn’t likely to change.

But Stewart is more than just a driver; he’s also an owner of the Stewart-Haas team  and his absence from the last three races has taken a toll.

“It’s just an emotional roller coaster all week, you know what I mean?” Greg Zipadelli, Stewart’s friend, former crew chief and competition director at Stewart-Haas, said (via Yahoo) Saturday night. “It is what it is.  We do the best we can with what we’ve got right now. We’ll keep praying, keep our fingers crossed that we get the boss back sooner rather than later.”

The investigation by Ontario County (N.Y.) authorities is expected to conclude soon, but it isn’t clear when or whether Stewart will race again this year. Regan Smith subbed for Stewart in the Watkins Glen race the day after Ward died and Jeff Burton has filled in the last two races. The next race is Sunday night in Atlanta and there’s no word yet on whether Stewart will drive. Zipadelli has been pleased, though, with the job Burton has done under difficult circumstances.

“It’s big shoes to fill, you know? He did a really nice job, he’s done a really classy job the last couple of weeks and that’s what we needed,” Zipadelli said. “This team needed that, somebody that would be there for them and work through these tough times.”

The Washington Post's Cindy Boren describes the fatal accident Saturday night at a dirt-track race in Canandaigua, N.Y., where Tony Stewart's car struck and killed fellow driver Kevin Ward Jr. The popular NASCAR driver, who was a regular on the dirt-track circuit, now faces an uncertain racing future. (Jhaan Elker and Kate M. Tobey/The Washington Post)