Roy McCauley, the crew chief for 2004 Nextel Cup champion Kurt Busch, will take a leave of absence from Penske Racing's traveling crew to spend time with his ailing wife.
Amy McCauley was diagnosed with Leukemia in February.
"But, there have been recent complications stemming from her long-term treatment and I feel as though I need to spend more time by her side,'' McCauley said. "In the interim, I will maintain an active role with our team from a communications standpoint, but Troy Raker will be in charge, leading the team and working with Kurt on a daily basis at the race track.
"Amy is receiving the best care possible and we're confident we will win the battle we are facing."
Busch and Raker will team together for the first time this weekend at Texas. Busch is 17th in points after finishing 12th in the last race at Martinsville.
David Newton covers NASCAR for ESPN.com. He can be reached at firstname.lastname@example.org.