Grant Cohn: The winner of Monday's 49ers-Vikings game will be ...

In their season opener Monday night, the San Francisco 49ers will play one of the up-and-coming teams in the NFL — the Minnesota Vikings. Here are five reasons the Vikings will win.

If I'm wrong and the 49ers win, I know you'll go after me and I'll deserve it. This is how I see it. No apologies.

1. San Francisco's pass protection

On certain days during training camp, the 49ers defense would practice blitzing. And on those days, the 49ers offensive line would give up nine or 10 sacks. Just one after another. Not real sacks — the defense can't hit the quarterback in practice. But in a real game, Colin Kaepernick would have gotten smashed.

The Niners have exactly two outstanding offensive linemen — Joe Staley the left tackle, and Alex Boone the left guard. The center, Marcus Martin, is a fill-in. He's starting until Daniel Kilgore returns from a broken ankle he suffered last season.

The right tackle, Erik Pears, also a fill-in, is starting because Anthony Davis decided to retire during minicamp. Pears should be a solid player. He has started 86 games in the NFL.

And the right guard, Jordan Devey, is a fill-in who's playing because 2014 third-round pick Brandon Thomas and 2015 sixth-round pick Ian Silberman aren't ready to start.

As currently constructed, the 49ers have one of the worst offensive lines in the NFL, lacking both talent and cohesion. Devey still hasn't played with the starters in a game. Meaning Week 1 is the first time these five offensive linemen will play together.

Vikings' head coach Mike Zimmer calls some of the most exotic blitzes in the league. He's going to test the Niners offensive linemen often to see how well they communicate and work together. They may flunk.

2. San Francisco's defensive coordinator

Eric Mangini may turn out to be a fantastic defensive coordinator for the 49ers.

But Monday night will be the first game he has called plays since January 14, 2006 when his New England Patriots defense gave up 27 points to the Denver Broncos in the divisional round of the playoffs.

Monday night also will be Mangini's first game calling plays without the help of Patriots head coach Bill Belichick – one of the best defensive coaches in the NFL.

Belichick's assistant coaches rarely succeed once they leave the Patriots. Will Mangini succeed?

Maybe, but probably not Week 1. He has to go up against Vikings offensive coordinator Norv Turner, one of the best play-callers in the league since 1991.

Turner will school Mangini.

3. Minnesota's play-action passing game

One way Turner will school Mangini: the play-action passing game.

The Vikings didn't have one last season without running back Adrian Peterson. Quarterback Teddy Bridgewater completed just 56.4 percent of his play-action passes while averaging only 6.1 yards per play-action attempt and posting a grotesque passer rating of 63.8 on those plays, according to Pro Football Focus.

But on regular passes — non-play-action passes — Bridgewater was outstanding. He completed 67.1 percent of his passes, averaged 7.7 yards per attempt and posted a passer rating of 92.4. He did this as a rookie.

By the end of the season, he was one of the best quarterbacks in the NFL. The final five games, he posted a passer rating of 102.9. And he didn't have a play-action passing game to make things easier. He was operating with the highest degree of difficulty.

Things will be much easier for him Monday night. Play action involving Peterson will create voids in the middle of the 49ers defense, behind the inside linebackers and in front of the safeties. Norv Turner will take advantage of those voids.

4. NaVorro Bowman's knee

Bowman is coming off a torn ACL and MCL and, if he has one weakness, it's pass coverage. He still seems a bit tentative and stiff while dropping back and changing directions. He seems much more effective bursting upfield to stop the run.

Bowman probably will play every snap with the base defense on first down and second down — running downs — and then sit on obvious passing downs like third-and-more-than-four.

The Niners will try to hide him in pass coverage, and Turner won't let them. Expect Turner to attack Bowman in pass coverage on first and second down. Expect Bridgewater's play-action passes to go Bowman's direction.

And expect Bowman to seem overwhelmed for the first time in his career.

5. San Francisco's cornerbacks

The 49ers top-three cornerbacks are Tramaine Brock, Kenneth Acker and Keith Reaser. Acker and Reaser are a couple of second-year players who spent their rookie seasons on the Injured Reserve list. They've played zero games in the NFL.

Brock is a six-year veteran who played just three games last season. He missed the other 13 games with toe, ankle and hamstring injuries. And the hamstring still bothers him. It forced him to sit out portions of practice this week.

So the Niners have three question marks at cornerback.

While the Vikings have three proven wide receivers — Mike Wallace, Charles Johnson and Jarius Wright.

Combined, they made 140 catches last season.

Across the board, Minnesota's receivers have the advantage over San Francisco's corners. Bridgewater can take his pick of whom to go after.

Final score: Vikings 23, 49ers 13.

Grant Cohn writes sports columns and the 'Inside the 49ers' blog for The Press Democrat's website. You can reach him at grantcohn@gmail.com.