Arizona’s Kurt Warner says he had his “best day yet” since sustaining a concussion two games ago. Still, Warner split practice time with backup Matt Leinart on Wednesday as coach Ken Whisenhunt and his staff took a cautious approach to handling the 38-year-old quarterback’s head injury. Whisenhunt said he hopes to avoid waiting until game time to name a starting quarterback for Sunday night’s game against the Minnesota Vikings. “It’s really about Kurt and where he is as far as improving and how comfortable he is with his health status,” the coach said.