The great Baltimore Colts quarterback Johnny Unitas was a broken-down San Diego Charger when the end arrived at 40 years and 153 days of age.

In his fourth and final start as a Charger, Johnny U. threw nine first-half passes in a loss at Pittsburgh. He completed two for 19 yards, two interceptions, a 0.0 passer rating and spent the rest of his 18th and final season on the bench behind rookie Dan Fouts.

That was 1973 and my first memory of what a 40-year-old NFL quarterback looked like.

Boy oh boy, has the graybeard bar been raised.

The Patriots’ Tom Brady was 171 days past his 40th birthday two Sundays ago. In his seventh consecutive AFC Championship Game, he reached his eighth Super Bowl by throwing two fourth-quarter touchdown passes to overcome a 10-point deficit and show once again why he’ll go down as the best player in NFL history. And, oh yeah, he did it with 12 stitches in his throwing hand.

“I’m watching the game and thinking, ‘If Jacksonville doesn’t make this first down, they’re going to lose, no doubt about it,’ ” Hall of Fame coach Tony Dungy said. “When they punted, I think we all said, ‘Well, we know how this one’s going to end.’ ”

With all due respect to Jim Thorpe, Bronko Nagurski, Jim Brown, Jerry Rice, Walter Payton, Lawrence Taylor and all the other legends of this 98-year-old league, no one can match Brady’s longevity of sustained greatness right now, let alone the day his career does finally end.

The 18-year veteran is expected to win his third league MVP award Saturday night on the 16th anniversary of his first Super Bowl victory. Think about that.

The next day, he’ll try to become the first player to win six Super Bowls when he faces the Eagles at U.S. Bank Stadium.

“To be in this game just one time is a dream come true,” Brady said. “But I don’t think about my legacy. What happened in the past is great. But that’s not going to win us anything on Sunday.”

Dungy said Brady “has been blessed” to have everything line up perfectly for him.

“Had Jimmy Johnson stayed in Dallas, Troy Aikman might have won five Super Bowls,” Dungy said. “For Tom, to have the drive, the competitiveness, the good health, the same coach in Bill Belichick, the same system, it’s just the perfect storm and probably will never happen again.”

Tony, I’ll see your probably and raise you to never. Through the TB12 sports therapy program he co-founded with personal trainer Alex Guerrero, Brady is mastering the science of stiff-arming Father Time physically, dietetically and mentally with a goal of playing at this level until he’s 45.

As far as the recent ESPN exposé on alleged rifts between Brady, Belichick, Guerrero and owner Robert Kraft, all the parties involved have tamped that down as overblown and nothing that’s going to topple the Big Three of Belichick, Brady and Kraft from making a run at Super Bowl No. 9 this fall.

Offensive coordinator Josh McDaniels laughed when asked if he thinks there’s a chance Belichick won’t be coach of the Patriots next season. He laughed even harder when asked if he senses Brady and the 65-year-old Belichick slowing down.

“No,” he said, pausing to laugh and smile before shaking his head and repeating the word “no” three more times.

The NFL has nine All-Decade teams going back to the ’20s. There are 19 quarterbacks on those teams. Only four have played beyond their 40th birthday. None has made two All-Decade teams, but one of them — Brady — will when this decade ends.

Refusing to lose

If Brady wins Sunday, he will have won three Super Bowls in a four-year span in two separate decades with 13 years in between.

“His will to compete is unmatched,” Patriots backup quarterback Brian Hoyer said.

Hoyer sees that incomparable will even when the two of them are competing after practice to see who can thrown more footballs into a bucket from 40 yards.

“Tom doesn’t lose, he just keeps the game going until he wins,” Hoyer said. “That’s the type of ferocity he has to win.”

Earlier this week, Brady released the second installment of his six-part Facebook docu-series. The episode entitled “The Mental Game” is a fascinating peek inside the unsatisfied mind of a man who already has done it all, and then some.

The episode begins with Brady working tirelessly on his throwing mechanics with Tom House, the former major league baseball pitcher turned passing guru.

“Old age and treachery always overcomes youth and exuberance,” House says. “He went through his youth and exuberance. He’s into his old age and treachery right now. But he’s mastered probably as much or more information and instruction than probably anybody in the history of football.

“And he’s still on the journey.”

Until Brady went 15-3 — and counting — this season, Brett Favre set the bar for wins by a quarterback after turning 40. He went 14-13, including a playoff victory.

But the old gunslinger’s offseason preparation was as old-school wing-it as Brady’s is new-school precision. After leading the Vikings to the NFC Championship Game at 40, Favre’s ending was ugly at 41 in 2010.

“The game now for me is very calculated,” Brady said in the Facebook docu-series. “It’s very strategic. It’s much more like chess than checkers.”

He says he watches tape “all day” Mondays and Tuesdays, after practice on Fridays, again on Saturdays and before games on Sundays, constantly looking for “tells” in the defense he’s about to face.

“I don’t know why I can sit here and watch it and process information quickly, but I can,” Brady said. “I can literally like just watch film all day. It’s almost like soothing because I’ve been doing it so long. I can just go four or five hours without getting up from this chair.”

Young teammates often view Brady as some sort of museum exhibit when they first meet him.

“I remember when we drafted [strong safety] Patrick Chung [in 2009],” Brady said. “He came up to me and was like, ‘Wow. Tom Brady.’ I said, ‘Damn, Pat, I’m not that old.’ At the time.”

Hoyer said he’s never talked to Brady about how many more years he’ll play.

“I haven’t because I see how well he’s playing,” Hoyer said. “I’m not going to ask because there’s no need to bring it up.”

Brady now has a family, which he said makes it a challenge to “find the right balance.” But, never fear, Pats fans, he sounds like he’s struck the perfect balance.

“I never want to be the reason why we lose a game,” Brady said in the Facebook docu-series. “I think about losing for days. … It can feel just like a game, but because it’s more than just a game to me, it feels like I’m losing in pursuit of what my life is.

“Thank God there’s another game next Sunday.”

For Tom Brady, there’s always another game next Sunday.


Mark Craig is an NFL and Vikings Insider. Twitter: @MarkCraigNFL E-mail: