TEMPE, Ariz. -- 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.
By contrast, Warner took all the first-string reps in practice last week only to sit out Sunday's 20-17 loss at Tennessee, snapping his string of 41 consecutive starts.
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.
Warner said Wednesday that the hard-to-describe "fogginess" behind his eyes has disappeared.
"These last few days have been a whole lot better, a lot more clear," he said. "I haven't felt that sensation the last couple of days. Again, progress. We are watching everything and making sure we continue to move forward. I am definitely feeling signs and seeing signs that I am improving."
One lingering symptom, he said, is a slight sensitivity to light.
He said that an examination by a specialist showed no damage to his eyes.
Warner was hurt when his head was slammed to the turf in the second quarter of Arizona's 21-13 victory at St. Louis on Nov. 22. He stayed in the game to direct the Cardinals' third touchdown drive, then sat out the second half.
The Cardinals prepared all of last week as if Warner would start, but the lingering symptoms led him and the team's medical staff to decide he should sit out the game. That thrust Leinart into the lineup -- his first start in two years -- even though he had only a few reps with the starters during the week.
"It was good to get out there and get some more reps today," Leinart said Wednesday. "I'm kind of playing it by ear, but I'm just going to prepare like I'm starting. That's really the only thing you can do."
Against Tennessee, Leinart was 21 of 31 for 220 yards and directed an 80-yard touchdown drive that put Arizona ahead 17-13 early in the fourth quarter.
Warner ranks fourth in the NFC in passing, behind Drew Brees, Brett Favre and Aaron Rodgers. He has completed 67.5 percent of his passes for 2,718 yards and 20 touchdowns with 11 interceptions, five in one game. In the six quarters since throwing those five picks against Carolina, Warner was 66 for 88 (75 percent) for 804 yards and nine touchdowns with no interceptions.
His presence could be crucial for Arizona (7-4) in its nationally televised game against Brett Favre and the powerful Vikings (10-1). A Cardinals loss and 49ers victory over Seattle would cut Arizona's NFC West lead to one game heading into a Monday night showdown Dec. 14 in San Francisco.
"I'm very optimistic, with what I feel right now and where I am improving, that I'll be out there Sunday," Warner said. "I don't want to give anybody a false impression. I don't want to make any statements that I'm definitely going to be out there, but I'm progressing and believing that I'm going to be there Sunday night."