I've seen George Malauulu tear up his knee while running the option at Cal. I remember Bobby Watters, his thumb shattered, in so much pain he couldn't watch the rest of an Arizona loss at UCLA.
I've seen John Conner lose his senior season, his knee busted, in a season opener against Fresno State, and my football-recall function hasn't lost memories of Brady Batten, Willie Tuitama, Keith Smith and Ronald Veal lying on the turf, worried that something was twisted, broken or dislocated.
Quarterbacks are in such a fragile pose, especially Arizona quarterbacks, that when Nick Foles' right knee was wrecked Saturday night in Pullman, Wash., you immediately knew the drill: The Wildcats will have to win with defense from now until December the same way they did it with Larry Smith and Dick Tomey.
Larry Foles, Nick's father, his ears covered to protect them from the evening chill, stood near his son on the Arizona sideline Saturday night at Martin Stadium. He wasn't there to watch Matt Scott preserve Arizona's 7-0 lead and eventual 24-7 victory. He was there to comfort his son, who, in an instant, saw his chances to take Arizona to a place it had never been go poof.
In a split second, everything changed for Foles and for his team.
This isn't to say the Wildcats won't be able to match their 5-1 half-season with a 5-1 second half, nor is it to suggest that Scott won't become a capable Pac-10 quarterback.
I've seen too many emergency quarterbacks, be they Jeff Hammerschmidt, Chuck Levy or Ortege Jenkins, help to save a winning season at Arizona.
But at Arizona, always, those seasons-in-distress were saved because the defense had a game-changer like Dana Wells or Tedy Bruschi, and because the man punching up the defense, Moe Ankney or Larry Mac Duff, was among the best in the business.
That's where UA co-defensive coordinators Tim Kish and Greg Brown, and senior defensive linemen Brooks Reed, Ricky Elmore and Lolomana Mikaele stand today.
They are the UA's new go-to guys in a stretch of games against Washington, UCLA, Stanford and USC.
"We've got a lot in front of us," Mike Stoops, the headmaster of that defense, said late Saturday outside the UA dressing room. "But whatever we do, we have to play better than we did tonight."
It's concerning that the Wildcats have not played well since beating Iowa in what seems months. They played flat and won against Cal, lost their edge and blew a tight game against Oregon State and beat Wazzu on Saturday because, truthfully, Wazzu isn't good enough to beat anyone else in the Pac-10.
But through six games, Arizona's body of work as a defense is compelling.
The Wildcats are No. 10 nationally in total defense (284 yards per game) and No. 7 in scoring defense (13.3 points per game). With Elmore and Reed combining for 10 1/2 sacks, Arizona is No. 3 nationally in sacks (3.5 per game).
How far can that take them? Can they even break even, 3-3 down the stretch, to take an 8-4 record into a bowl game?
I don't see why not. But do not count on any more comfortable fourth-quarter leads.
"Arizona's defense was pretty good," said WSU quarterback Jeff Tuel. "Obviously, they caused some problems in the backfield quite a few times. They are real physical, real fast, probably the best, if not the best, defensive line we have faced this year, in my opinion."
The Cougars have played USC, Oklahoma State and Oregon, so Tuel's opinion carries some weight.
Said WSU coach Paul Wulff: "Arizona's defensive speed, and their two defensive ends, are very good. They are senior veteran players. Their one defensive tackle is a senior and they are just very veteran, good stout players that have been there a long time. They disrupted us enough to create problems."
The Pac-10 is a passer's league, a high-scoring, gotta-get-30-to-have-a-chance business these days. Washington, for example, is a .500 team not far removed from an 0-12 year that averages 412 yards per game. But the Huskies remain a middle-tier squad because their defense gives up 417 per game.
The themes change now. Instead of Foles vs. Jake Locker, or Foles vs. Andrew Luck, it will be Arizona's defense on the marquee.
For the UA to be successful, Stoops will have to reinvent this team on the run.
Contact columnist Greg Hansen at email@example.com or 573-4362.