Tony Stewart won his third NASCAR championship Nov. 20. (Chris Graythen / Getty Images)

When it became known before winning his third NASCAR championship last week that Stewart had already made the decision to part with Darian Grubb, speculation immediately focused on Steve Addington, Kurt Busch’s chief.

Today, the move to Stewart-Haas Racing became official.

“My comfort level with him is already strong,” Stewart said of Addington in a statement. “He balances the technical part of our sport with the real-world experiences we get at the track, and that will allow for a smooth transition as we prepare to defend our title in 2012.”

The stars aligned last week when Grubb said he’d been told midway through the Chase that his services would not be retained in 2012. And Addington told Penske Racing he was leaving.

“[Stewart] expects a lot and he knows a lot,” Addington said in the statement. “His talent behind the wheel is obvious, but his ability to motivate and get everyone to believe that whatever goal they set is attainable is something every crew chief wants, and I plan to make the most of it.”

Returning to Hendrick Motorsports is a possibility.

“I have had discussions with Darian,” Hendrick owner Rick Hendrick told ESPN. “hen he left, we told him we'd always have a place for him if he wants to come back. Darian is a pretty smart guy. I know he's entertaining a lot of offers.

“We don't have a crew chief role. We have an engineering role we think Darian would be real good in. We'd love to have him back in the organization. I quite honestly don't know where he's going to end up.”