MINNEAPOLIS—The Seahawks started Sunday's game on a very positive note, with Russell Wilson and the offense driving down the field for an opening-drive touchdown, but the Vikings answered right back with a quick scoring drive of their own, setting the tone for what would end up being a very tough day for Seattle's defense.

And while Minnesota's offense never really cooled off, the Seahawks couldn't match that production in the second half, and the result was a 30-17 loss that dropped Seattle's record to 1-2.

Here are five rapid reactions to Sunday's loss:

1. The defense has a lot to clean up.

The Vikings are a very good offensive team, even with Pro-Bowl running back Dalvin Cook out with an injury, so nobody was expecting it to be an easy day for Seattle's defense. But no matter the opponent, the Seahawks expect to be better on defense than they were on Sunday when Kirk Cousins and company had a huge day to lead the Vikings to their first victory of the season.

The Seahawks started the season looking pretty solid on defense with a strong showing against Indianapolis, and also played well in the first half against Tennessee, but the last game and a half have seen opposing offenses moving the ball too easily.

On Sunday, the Vikings scored on six of their first seven possessions, had 453 total yards, and were 9 for 14 on third down, including conversions on six of their first seven third downs.

2. The Seahawks second-half offense hasn't matched the first-half production.

For the third straight week, the Seahawks offense got off to a fast start, putting together a 75-yard touchdown drive to open the game, followed by a field goal and another touchdown. But for the third straight game, the Seahawks also failed to score in the third quarter, and they had only six first downs, one of them by penalty, on four second-half possessions, including two five-play possessions to start the half while it was still a one-score game.

With all the talent Seattle has on offense, and with the strong play in the first halves, there's plenty of reason to be optimistic about that unit going forward, but the Seahawks are going to need more complete four-quarter performances to win more games.

3. DK Metcalf had his best game of the season.

If there was a bright spot in an otherwise rough day for the Seahawks, it was the performance of receiver DK Metcalf. After a relatively quiet first two games, Metcalf got involved early, catching three passes on Seattle's first drive, including a 10-yard touchdown. Metcalf also had a key block on Chris Carson's 30-yard touchdown run in the second quarter. Like the rest of the offense, Metcalf did most of his damage in the first half with five catches for 88 yards, and he finished game with six catches for 107 yards, both season highs.

4. Chris Carson had a big first half.

With the offense not able to sustain drives in the second half, Chris Carson didn't see much of the ball, carrying only twice for 6 yards, but Seattle's running back was very impressive in the first half, rushing 10 times for 74 yards, including a 30-yard score.

The touchdown was Carson's third in the past two games.

5. The Seahawks are in a hole in a very tough NFC West.

It's still very early in the season, but the Seahawks have some work to do if they're going to put themselves in a position to defend their NFC West title. Both the Cardinals and Rams won Sunday to improve to 3-0, while the 49ers, Seattle's Week 4 opponent, lost to the Packers Sunday night to fall to 2-1.