With his injuries outnumbering the weapons around him, McNair has carried Tennessee from a 1-4 start to today's AFC championship game against the Raiders.
Despite playing with sprained toes, he scrambled and dived for first downs. Despite playing with banged-up ribs, he escaped the clutches of pass rushers. And despite playing with a sore back, he waited to deliver the pivotal throw even though a hit soon followed.
But the defining moment of McNair's season so far came Saturday, when he couldn't grip the ball because of a thumb injury but still strong-armed the Titans to a 34-31 overtime victory over the Pittsburgh Steelers.
"Injuries are part of the game and I'm used to it," McNair said. "This is the style that I play -- being physical, running the football, making adjustments on the pass and avoiding the rush. Those sorts of things go with the total package of a quarterback."
Snubbed in the Pro Bowl voting, McNair made the playoff game against the Steelers his stage.
When running back Eddie George was knocked out of the game with a concussion, McNair pulled the Titans from a 20-14 deficit to a 28-20 lead by completing nine of 10 passes for 112 yards on two touchdown drives.
Then, late in the fourth quarter, McNair slammed his right hand into a helmet, numbing his thumb and preventing him from gripping the ball. Doctors cut off a piece of hanging flesh from the thumb and bandaged it.
After missing two plays, he approached Coach Jeff Fisher.
"He simply said, 'I'm going to play,' " Fisher said.
With the bad thumb, McNair finished by completing six of 10 passes for 94 yards, including a spike to stop the clock. He marched the Titans from their 31 into range for the game-winning field goal in overtime by hitting Justin McCareins on passes of 31 and 22 yards.
McNair likely will be listed as questionable for today's game with the thumb injury.
"You didn't think anything was hurting on him," McCareins said. "We believe in him all the time. That's Steve for you."
McNair's impact is even greater when looking at his supporting cast.
The inconsistency of George was the major reason Tennessee ranked 26th in yards per carry (3.8). And receivers Derrick Mason and Frank Wycheck don't really compare to the Raiders' combination of Jerry Rice and Tim Brown.
Plus, injuries kept McNair from completing a full practice from Nov. 22 until the end of the regular season. All of that mattered little to McNair, who has a 7-2 record this season against teams that finished with a winning record.
"He's improved a lot," said Raider safety Rod Woodson, who had played against McNair in the past with the Ravens and Steelers. "He's been banged up a lot this year, but I think he's been more focused."
Four months ago, McNair had one of his worst performances of the season in a 52-25 loss at Oakland. He threw for a career-high 398 yards but also threw a career-worst four interceptions.
But that game occurred before the injuries started mounting along with the victories.
While on the injury report from Week 9 to the end of the regular season, McNair completed 58 percent of his passes for 1,701 yards and 10 touchdowns as the Titans won eight of their last nine.
But grit -- not statistics -- has been the true measure of McNair.
"The man, to me, is a legend," George said. "I'm so glad we're able to advance so people can really appreciate Steve's performance and what he's done this year."