The trauma being felt by Vikings fandom over Teddy Bridgewater's injury has only one comparable in team history. That would be the absence of Joe Kapp entering the 1970 season.

The criteria for assessing the level of emotional angst would be the Vikings losing he anticipated quarterback before the first game was played. There have been numerous in-season injuries to quarterbacks, but only Kapp had the locals so hyped for success and then wasn't present for the opener.

The actual reasons for the absence are far different:

• Bridgewater suffered an injury to his left leg that could cause him to miss two seasons and led to Saturday's acquisition of Sam Bradford.

• Kapp decided to become a pioneer in the players' battle for free agency, didn't show up for 1970 training camp and never played again for the Vikings.

The similarities are this:

• As details emerged Tuesday of Bridgewater's misfortune, it seemed incomprehensible that such an injury could occur in a routine, no-contact situation.

• As details of Kapp's potential holdout arrived out of nowhere in July 1970, it seemed incomprehensible to Minnesotans that the beloved Hennepin Avenue Joe wouldn't want to be here to lead another run to the Super Bowl.

Kapp had aligned himself with agent John Elliott Cook to challenge the Rozelle Rule, the NFL edict that basically prevented players from signing elsewhere.

The Vikings were a team built on magnificent defense in the first Super Bowl season of 1969. Kapp was in his third season and didn't start the opener, a 24-23 loss on the road to Fran Tarkenton and the New York Giants.

The home opener was on Sept. 28 at Met Stadium. Kapp threw for seven touchdowns in a 52-14 slaughter of Baltimore. That game turned Kapp into the Vikings' heroic leader, even with what would become an erratic season statistically.

You look at Kapp's numbers now in contrast to the NFL's current efficient quarterbacking and they wouldn't hack it.

Back then, with that defense and Kapp's giant personality, his loss before the season started was a kick to the stomach. The Vikings have softened the Bridgewater kick to today's fans by bringing in Bradford.

PATRICK'S PLUS THREE

Life immediately after Joe Kapp:

1970: Vikings defense gave up 143 points in 12-2 season. Quarterback Gary Cuozzo was woeful in 17-14 home playoff loss to 49ers.

1971: Defense gave up 139 points in 11-3 season. Cuozzo and Bob Lee played in 20-12 home playoff loss to Cowboys on Christmas Day.

1972: Fran Tarkenton returned in a trade. Vikings went 7-7, but three Super Bowls with Tarkenton would follow.

Read Patrick Reusse's blog at startribune.com/patrick. E-mail him at preusse@startribune.com.