Like a car that is making a strange noise, shakes on turns and emits a trail of smoke, the Vikings need a full diagnostic test after their second second-half collapse of the season Sunday.

A popular sentiment when things unravel like they did for the Vikings in a 24-20 loss to the Tampa Bay Buccaneers is to blame a team's adjustments, or more specifically, the absence of them. We're not buying that line of thinking in this particular case.

The Vikings' latest meltdown had nothing to do with halftime adjustments and everything to do with execution. The Bucs made plays when they had to, and the Vikings didn't, plain and simple.

Between missed tackles, senseless penalties and just poor execution, the Vikings allowed their 17-point lead to deteriorate before their eyes. They made too many mistakes, and this team simply is not good enough to play that way and win, no matter how comfortable a lead looks.

That's what made Bucs coach Raheem Morris' postgame synopsis so refreshing. Asked specifically about his halftime adjustments, Morris admitted they stuck with the same game plan. His players simply executed better in the second half.

Coaching adjustments undeniably are an essential component of successful teams. Whether it's using a no-huddle offense to catch an opponent off-guard, adjusting coverages in the secondary or making other in-game changes, teams must be able to adapt and counter.

What happened Sunday in the second half looked more like the result of sloppy execution than a lack of effort or a flawed plan.

"It's not so much strategy," Vikings coach Leslie Frazier said. "We've just got to mature as a football team."

This is not meant to absolve Frazier and his staff of any blame. Frazier's reasoning for not using timeouts once the Bucs moved into chip-shot field-goal range inside of two minutes was completely baffling. Frazier said he didn't call a timeout because he felt his team would stop the Bucs. A field goal was practically a given at that point so the Vikings needed as much time as possible when they got the ball back. Instead, they took over with 24 seconds remaining.

Offered a chance Monday to reassess his decision, Frazier called it "debatable" but stopped short of saying he should have handled it differently.

Still, the Vikings shouldn't have even been in that position, and they know it.

"The Vikings beat the Vikings," Visanthe Shiancoe said.

"It's us," Percy Harvin said. "It's all us."

Sort through the debris and you find individual plays that undermined their ability to seal the deal.

Brian Robison jumped offsides on a play on which the Bucs fumbled. "It's something that's inexcusable and can't happen," Robison said.

Antoine Winfield, one of the best tackling corners in the NFL, slipped off Preston Parker on a third-and-12 pass play. The Bucs would have had to punt if Winfield made the tackle. Instead, Parker gained 51 yards and they ended up with a field goal.

Jared Allen was called for roughing the passer after he unnecessarily hit Josh Freeman after a throw, costing the defense 15 yards. The Bucs scored on a 25-yard touchdown catch by Arrelious Benn on the next play. Allen called it a "knucklehead move on my part."

Lorenzo Booker unwisely returned a kickoff 6 yards deep in the end zone and got stopped at the 9-yard line with his team trying to hang on for dear life.

Tyrell Johnson dropped what should have been a game-saving interception on the Bucs' final drive.

Those were critical mistakes by veteran players. They weren't the only ones either. That, more than anything else, is why the Vikings were kicking themselves after their latest second-half flop.

"We talk about being a smart football team and not doing things to hurt ourselves," Frazier said. "We definitely hurt ourselves yesterday with some key penalties in crucial situations. We've got to get better at handling those situations and not hurting ourselves if we want to be a good football team. If you shoot yourself in the foot like we did a couple of times you end up in close ball games where it ends up biting you."

Chip Scoggins • ascoggins@startribune.com