Kirk Cousins' rattled play costs John DeFilippo his job and could cost Mike Zimmer his

Kirk Cousins is shrinking before our eyes, melting like sugar in hot tea, and unlike his frazzled and frayed predecessors, he is capable of detonating an entire franchise.

Cousins' wobbly kneed performance Monday at Seattle got offensive coordinator John DeFilippo fired, a move that should be viewed as a preview of coming events should the current Vikings quarterback continue to look small as a theater mouse on a large stage.

If Cousins can't demonstrate more mental toughness in big games, if he can't deliver playoff victories to a team that signed him specifically to do just that, the general manager who paid him big money and the coach who was handed a fully funded team might be the next to forfeit their TCO Performance Center key cards.

Less than a year after playing in the NFC Championship Game with a backup quarterback, the Vikings are a .500 team with one of the league's most expensive. They remain likely to make the playoffs, but Cousins' inability to look even composed in three telling road games — at Chicago, New England and Seattle — has made the prospects of a playoff appearance unsavory.

The worst part of Cousins' implosion is that he looks unnerved. Having covered the NFL since 1989, I don't say this lightly.

Football players regularly display an astonishing level of physical bravery and mental fortitude. They accept a high risk of injury and the likelihood of pain. I wouldn't question a football player's resolve if squeamishness wasn't so obvious.

The Vikings would have been better off in their past three losses if Cousins had channeled his inner Favre and tried to wedge passes between defenders — or if he had channeled his inner Bridgewater and maintained his cool. The Vikings would be better off if his problem was throwing interceptions. It's easier to coach bad passes out of a quarterback than it is to teach aggression under pressure.

On his backward pass, he had Stefon Diggs open. He also could have taken a sack. Instead, he threw a risky pass with little chance of producing a positive play. Murray did well to avert disaster, but Cousins shouldn't have put him in that position.

On the fourth-down pass into the end zone, Rudolph was not open, and Adam Thielen, just a few yards away, was alone. The only way a quarterback throws that pass to Rudolph is if he had predetermined that he will have no time to read the defense after the snap.

Here's the problem: He did have time to recognize that Thielen was open for the touchdown.

There are other culprits here. DeFilippo wasn't able to help Cousins, develop a running game or conjure the magic that Pat Shurmur did a year ago. The offensive line has regressed since its good-enough performance of 2017.

Zimmer needs to prove, after the promotion of Kevin Stefanski to replace DeFilippo, that he can get along with at least half of the offensive coordinators he has employed. And there are those in the organization, and close to the organization, who believed that Stefanski should have gotten the offensive coordinator job when Shurmur left. If Stefanski outperforms DeFilippo, the Vikings' brain trust will have another decision for which to answer.

The Cousins signing changed everything for Zimmer and the Vikings, turning them from a team admirably doing its best with what it had at quarterback into one supposedly built to win big. High expectations can end careers.

Cousins was supposed to erase the stigma of the Vikings' decades-long inability to develop their own starting quarterback. Instead, in three nights in the mist and cold of a budding winter, he has endangered his reputation and the jobs of the people who depend on him.

Jim Souhan's podcast can be heard at TalkNorth.com. On Twitter: @SouhanStrib. • jsouhan@startribune.com