Norv Turner's resignation apparently makes him the scapegoat for the Vikings' performance over the past two games. But we must not forget that the team was 5-0 with Turner calling the plays and there was talk of the team going to the Super Bowl.

The simple fact is that the offensive line is in shambles, and the offense as a whole ranks 31st in the NFL.

If you want my opinion on the Vikings' current situation on offense, it all started to fall apart when center John Sullivan got injured and missed the 2015 season. Sullivan tried to come back but wasn't himself physically and the Vikings released him.

It's true that center Joe Berger had a big year filling in for Sullivan, and Adrian Peterson led the league in rushing. But even though Berger is an outstanding center, he may not have the leadership qualities and the ability to call signals at the line that Sullivan had. When they lost Sullivan, they lost their top leader on the offensive line and that unit simply went backwards. And if Sullivan were available, Berger could be filling in at one of the other holes in the offensive line.

Injuries happen in football, and there's a reason that the Vikings focused all of their efforts and attention in the offseason on bringing in offensive line talent to build competition.

Back in March, CBS reported that after the Vikings signed free agents Andre Smith and Alex Boone, the team had the highest-priced offensive line in the NFL, with 28 percent of their salary cap going to those positions.

But the news of Sullivan being released in August meant that what looked like a position of strength was in trouble.

And now the team has lost Matt Kalil and Smith to season ending injuries, then Phil Loadholt's injury setbacks forced him to retire, Boone got injured in Chicago, and Jake Long — who hadn't started a game in two years, isn't looking like he's ready to be a permanent replacement. There's also T.J. Clemmings at right tackle, who hasn't been drawing praise from coach Mike Zimmer. And with Loadholt out of the lineup, Brandon Fusco is not the performer he was with Loadholt in the game.

Offensive struggles

The last time the Vikings had a dominant offense was in Sullivan's first season as the starting center in 2009. With quarterback Brett Favre and Peterson having amazing seasons. the team posted the fifth-best total offense in the NFL with 6,074 yards.

Since then things have been abysmal.

They ranked 23rd in 2010 with 5,029 yards, 18th in 2011 with 5,275 yards, 20th in 2012 with 5,385 yards, 13th in 2013 with 5,508 yards, 27th in 2014 with 5,048 yards and 29th last season with 5,139 yards.

When they hired Turner before the 2014 season, he was viewed as being in total control of the offense under Zimmer, who would be more focused on his skills as a defensive specialist.

The team averaged 313.3 yards per game under Turner, that's the second-lowest yardage total over the past three seasons in the NFL, trailing only the Los Angeles Rams.

And consider Peterson, who had averaged 4.9 yards a carry over his long career, but was averaging a lofty l.6 yards per carry in the two games he played when he was healthy.

And now the work of offensive coordinator falls to Pat Shurmur, who has a long history with quarterback Sam Bradford and has been an offensive coordinator in St. Louis and Philadelphia. But Shurmur can't play offensive tackle or guard and he will have to be a miracle man to fix the team's big problem.

Gophers moving up

It's amazing to think that, if it wasn't for basically two possessions, the Gophers would be undefeated right now. Their tough losses against Iowa at home and at Penn State started their Big Ten season at 0-2, but now they have rattled off three wins in a row, are in second place in the Big Ten West, one game out of first. If they win out the rest of their games they will play in the Big Ten Championship.

Coach Tracy Claeys said that going forward the team is looking to get more dynamic running the ball, including with quarterback Mitch Leidner, who has rushed for touchdowns in each of the past two games and should get more opportunities to carry the ball.

Last week, Kobe McCrary even got back into action rushing for a touchdown on four carries. He had 176 yards rushing against Indiana State earlier this season but is now warming the bench.

"We have to find a way to get each of those backs [Rodney Smith and Shannon Brooks] around 20 touches per game," Claeys said. "If you watch college football, it comes down to quarterbacks making plays with their legs, whether they're designed that way or it's scrambles on passes. It goes back to being able to pick up an extra blocker. [Leidner] is a big kid and he runs well and he's hard to tackle for a loss."

Jottings

• While Claeys has the lowest salary for a football coach in the Big Ten at $1.4 million, he does have the potential to earn an additional $1.25 million in bonus money based on various conditions. That's the third-highest potential bonus earnings in the conference, trailing Kirk Ferentz at Iowa and Jim Harbaugh at Michigan. Last season Claeys made $157,942 in bonus money.

• As the Gophers prepare to face Purdue, one thing worth noting is that the Boilermakers have the third-worst turnover differential in the nation at minus-12, and the Gophers have the fourth-best turnover differential at plus-10.

• When Lou Holtz was coaching the Gophers, he and former Iowa coach Hayden Fry were trying to get the Minnesota State High School League to stage the all-star game at the end of the season when players are in game shape and ready to play. They are finally going to do this with Eden Prairie coach Mike Grant coaching the south squad while Totino-Grace head coach Jeff Ferguson will coach the north. The game will be at U.S. Bank Stadium on Dec. 3.

• The Vikings have dropped from second in the odds to win the Super Bowl to sixth, they now have 9/1 odds and are behind the Broncos, Packers, Seahawks, Cowboys and Patriots — who I believe are going to win the whole thing.

• Tuesday night marked the third time in franchise history that the Timberwolves started four players under the age of 22 in Kris Dunn, Zach LaVine, Karl-Anthony Towns and Andrew Wiggins. LaVine finished with 31 points on 11-for-18 shooting.

Sid Hartman can be heard weekdays on 830-AM at 7:40 and 8:40 a.m. and on Sundays at 9:30 a.m. shartman@startribune.com