SANTA CLARA, CALIF. — Oli Udoh almost jumped, like a frog touched on the rump.

Vikings quarterback Kirk Cousins, scrambling as the play clock ran down, from the 49ers 3-yard line, on what might have been the key play of the game, had lined up behind Udoh, the right guard, instead of the center. For a moment the deadly serious and frequently injurious sport of professional football became a sitcom, and Udoh all but levitated.

If that had been Cousins' only mistake, the Vikings might have won on Sunday, and everyone in the locker room could have a laugh at Udoh's expense. Instead, Cousins played his worst game in more than a calendar year, as the sitcom became a satire of his Vikings tenure in a 34-26 loss.

The Vikings fell to 5-6 and haven't been above .500 since the end of the 2019 regular season, and now Cousins might have to lug them into the playoffs without star running back Dalvin Cook or a defensive line.

At best, Cousins has been an elevated game-manager. Now he needs to prove he can elevate a franchise, justify his large paycheck and prove the impressive statistical profile he's built this season is more substantial than San Francisco fog.

"We're so close," Cousins said, and you wonder if he's been mumbling that to himself for two years.

Five moments defined Cousins' day and cost the Vikings a bushel of points:

1. At the end of the first half, the Vikings had moved to the 49ers 46 with 5 seconds remaining. On the next play, Cousins threw incomplete to an empty area of the sideline, then ran to the Vikings sideline, looking agitated. "Just wanted a field goal there," he said.

2. He entered the game having thrown only two interceptions this season. In the third quarter, he stared down receiver Adam Thielen, then threw a pass that was intercepted by the 49ers' Azeez Al-Shaair. It was the kind of mistake he had stopped making.

"Just a poor throw, poor read and made a poor decision," Cousins said. "Just got blocked out and shouldn't have thrown it."

3. After the Vikings scored to cut their deficit to five points in the third quarter, they went for a two-point conversion. Cousins rolled to the right, seemingly had room to run into the end zone but instead bounced a pass near the feet of a wide-open Justin Jefferson.

"Poor throw," Cousins said. "Felt like maybe I rushed it."

4. With the Vikings facing fourth-and-goal from the 49ers 3-yard line, the offense scrambled to line up correctly, with Cousins finding himself behind Udoh, prompting the Vikings to call timeout. Then Cousins, under pressure, threw a no-hope incompletion toward the back of the end zone. "We just didn't make enough plays," Cousins said.

5. On fourth-and-8 from the 49ers 38 with less than a minute remaining, Cousins had Jefferson running open for a first down over the middle and threw too high, prompting Jefferson to appear to yell to no one in particular. "I don't like to lose," Jefferson said.

Since scuttling the 2020 season with a series of grotesque interceptions in the first six games, Cousins has been remarkably accurate and careful. His statistics entering Sunday's game were those of an MVP candidate.

MVPs, though, are more about cause than effect, and today Cousins is 56-57-2 as an NFL starter and 12-15 since the Vikings' previous visit to Levi's Stadium.

The way players reacted to Cook's apparent shoulder injury on the field, no one should expect him back soon. Nor will the Vikings defensive line look anything close to whole the rest of the way.

The remaining strength of the Vikings roster is the passing game — Cousins throwing to Jefferson and Thielen. Can Cousins, armed with two star receivers, navigate a favorable schedule and lift the Vikings to the playoffs?

"I thought he played well," coach Mike Zimmer said.

Udoh's tickled rump and Jefferson's empty hands might argue. Funny as it looked, lining up behind guard with the game on the line is no way to goose a team into the playoffs.