Offensive coordinator Norv Turner isn’t ready to start handing out gold stars to his offensive linemen. Though he wouldn’t go into detail about what went wrong in last Sunday’s offensive letdown during the Vikings’ 20-3 to San Francisco, he said he needs better pass protection for his quarterback.

“We have a lot of work to do as an offensive group. It starts with, to me … eliminating unforced errors,” Turner said.

Turner admitted, though, that the game started badly with his quarterback. Teddy Bridgewater threw three consecutive incompletions on the Vikings’ first possession to squander great field position.

“Teddy missed some throws early that he normally makes. We had a lot of unforced errors where we created problems for ourselves,” Turner re-emphasized. “We’ve got to keep people from coming free at the quarterback. It’s hard to play when you have people running free at you and I think that will help a great deal.”

It will be necessary in Sunday’s home opener against Detroit. The division rival piled up 12 sacks over two games against the Vikings last season. Bridgewater surely hasn’t forgotten most of them. In only his second career start, Bridgewater was sacked eight times for 45 yards. He also threw three interceptions.

“If you dwell on that stuff from last year, there’s going to be a negative attitude,” left tackle Matt Kalil said. “So I think our thoughts are that we’re a lot better [this year], even though we didn’t show it Monday. But we definitely are improved, and I guess we can use it as motivation to not let it happen again.

“It’s a long season. I know last year when we had those pieces mismatched, we got a lot better toward the end of the year, but our plan is to get better right now and get stronger towards the end of the year.”

Kalil gave up a league-worst 12 sacks while playing on a bad knee last season, with 2½ of those sacks coming against Lions defensive end Ezekiel Ansah.

Kalil was arguably one of the bright spots on an otherwise poor offensive night Monday.

“I thought I played great,” Kalil said. “At the same time, it’s kind of bittersweet ’cause I care more about winning. Obviously you still want to play well, but the most important thing at the end of the day is winning games. So I can’t be completely happy. It’s a good start for the season, but I want to do well as a whole on offense.”

According to Pro Football Focus, he allowed only two quarterback hurries against the 49ers’ physical defense line. Kalil was asked to elaborate on why he thought he was “great” Monday, and he tempered his assessment.

“I thought I played well,” he said. “Obviously I want to keep getting better. Losing the game, I don’t feel too good about it.”

Zenner returns

Zach Zenner will return home this weekend as a member of the Lions. The Eagan native and former standout South Dakota State running back grew up a Vikings fan and now will get a chance to play on the same field against them.

The undrafted rookie was one of the top rushers in the NFL in the preseason with 35 carries for 183 yards and two touchdowns. He had two carries for 6 yards and played on the kickoff coverage unit in Week 1 against San Diego, a 33-28 loss.

Vikings coach Mike Zimmer is well aware of this local talent. “He’s got some explosiveness to the hole and has some physicality to him,” Zimmer said.

If Zenner is active for Sunday’s game at TCF Bank Stadium, he’ll likely continue to play a limited role for Detroit, which was powered by another rookie running back, second-round pick Ameer Abdullah, in the season opener.

Etc.

• Running back Jerick Mc­Kinnon (ankle) and defensive tackle Shamar Stephen (knee) were the only two Vikings on Thursday’s injury report. Both were listed as full participants in practice.