Mark underwent back surgery in the off-season to relieve pain from herniated discs that had plagued him for years. The surgery was considered a success and Mark had entered the season saying he felt better than ever.
"I did a lot more smiling the first half of this year than last year," he said. "I'm having a little bit of problems now, nothing like what I had. Things are not going as good the last three of four weeks as they had been, though."
Team members said last weekend at Sears Point was the first time Mark had made mention of his recurring back pain at the track. Mark also said Friday once his current contract expires in 2005 with Roush Racing, he will either retire or run a limited Winston Cup schedule.
"I'll be getting old by then and I might need a little bit more rest than these young guys," Mark, 41, said.
