EAGAN, Minn. – For the first time under Head Coach Mike Zimmer, the Vikings are 0-3 to start a season.

After losing to Green Bay and Indianapolis, respectively, without much of a fighting chance, Minnesota showed a new intensity against Tennessee and built a 12-point lead in the third quarter. The Vikings faltered, however, and found themselves unable to hang on in a 31-30 loss.

Zimmer spoke to Twin Cities media members on Monday after reviewing the tape from Sunday's game. He noted takeaways of the positive and negative variety.

"I thought there was a lot of good things that happened," Zimmer said. "We had almost 500 yards of offense. We rushed for over 200 yards. We held them to 23 percent on third downs. And I think [the Titans] were the No. 1 team in red zone [scoring]. We did a pretty good job after a sudden change."

Despite all of the above, though, miscues throughout the game – and especially in the final 15 minutes – were costly.

"Unfortunately, there were some mistakes there in fourth-quarter execution that we've got to get cleaned up," Zimmer said. "We're looking forward to getting back out and fixing those mistakes."

The Vikings now are one of eight NFL teams (four in each conference) to remain winless through three weeks and have fallen three games behind division rivals Chicago and Green Bay, both undefeated.

Zimmer said it's imperative that players "keep fighting" to right the ship.

"Everybody's got to continue to grind and keep doing their thing," he emphasized.

Here are four other topics Zimmer addressed during his media session:

1. Addressing the Achilles heel

The Vikings played better defensively than they did in Weeks 1 and 2, but they allowed the Titans to make explosive plays that ultimately were too tough to recover from.

Two such plays were allowed to Titans receiver Khalif Raymond, who hauled in passes of 44 and 61 yards. Raymond, whose previous single-game high was 52 yards, totaled 118 yards on three catches.

Titans quarterback Ryan Tannehill also connected with receiver Corey Davis for a 38-yard play on second-and-4 in the third quarter.

"We gave up three catches for 143 yards," Zimmer said. "One was a double move, and a couple of them were shots down the field. So that's kind of been the Achilles' heel the past three weeks."

2. Adding veterans in-season

Due to injuries and a lack of depth on defense, the Vikings have made a few additions to that side of the ball in-season. In addition to bringing back veteran safety George Iloka, Minnesota also recently signed sixth-year linebacker Todd Davis.

Iloka was signed to the Vikings practice squad but elevated to the active roster for Sunday's game, during which was part of six special teams plays. Davis, who had just two days of practice under his belt, played one defensive snap.

Considering the team's struggles on defense, Zimmer was asked if he might consider bringing in more veterans in the coming weeks.

"I just try to coach the guys we have here," Zimmer said. "They're always out looking for players, and we'll continue to get these guys better. They've improved every week."

3. Seeing the silver linings

It's tough to find the positives after three straight losses, but Zimmer said he's seeing growth from the young defensive players.

"I think the biggest thing is I keep seeing improvement from these young guys," he said.

Zimmer specifically pointed to rookie D.J. Wonnum, who has been involved the past two games (25 snaps apiece) in the defensive end rotation in Danielle Hunter's absence. On Sunday, Wonnum recorded three tackles and a tackle for loss.

Zimmer also has seen progress from the Vikings secondary.

"D.J. Wonnum has improved, the DBs have all improved," he said. "They've still got work to do before we can get to where we want to be, but they're all improving, and not having preseason with a young secondary, that's always difficult. They'll continue to get better."

4. Looking for 1st win

The Vikings will continue working to notch their first win of the season.

Their next opportunity will be Sunday, when they face a fellow 0-3 team in the Houston Texans.

How much would a win mean to Minnesota at this point?

"That's the disappointing thing, and what I told them in the locker room last night was, we work our butts off to do that and probably should have won the game yesterday and didn't win it," Zimmer said. "We work hard, and we don't have anything to show for it right now.

"It's disappointing, it's frustrating, it's all those things that you want to say," he continued, "but we've got to keep grinding, and hopefully the ball bounces our way and we'll get a win here this next week."