The Vikings are entering their fourth season under the guise of Head Coach Mike Zimmer. Minnesota's defensive coaching staff has also remained intact, including defensive line coach Andre Patterson.

But Patterson and Zimmer have known each other for much longer than their time in Purple.

*Star Tribune *columnist Sid Hartman **highlighted the longtime friendship** between the two coaches, who first worked together at Weber State University in 1988. Zimmer moved on to Washington State in 1989, and Patterson joined him there for the 1992 and 1993 seasons. Hartman wrote:

The next time they worked together, Zimmer hired Patterson away from his first stint with the Vikings. Patterson coached the [Vikings] line in 1998 and '99 but then joined Zimmer, who was defensive coordinator with the Dallas Cowboys. Patterson remained there for three seasons.

When Zimmer was hired as Vikings head coach in 2014, he made Patterson one of his first hires. Since then they have developed not only one of the best defenses in the NFL but a dynamic defensive line that finished tied for ninth in sacks (41) in 2014, tied for seventh (43) in 2015 and fifth (41) in 2016.

"Even during the years when we were not coaching together, we were in constant contact with each other," Patterson told Hartman. "I don't think we ever went longer than a week without talking to each other. Even during the football season. You know, he's my boss as the head football coach, and I respect him in that role. But most importantly he's a close friend of mine, and I know that he knows I'm going to do whatever he asks me to, to the best of my abilities."

Patterson described Zimmer as "an old-school football coach" who is tough but fair.

"They want their players to be tough," he told Hartman. "They want football to be played the right way and not break the rules and play within the rules, but play hard and play physical.

"He is going to do everything in his power to make sure his players improve," Patterson added. "He's never a guy to sit around and talk about what he doesn't have. He wants to take what he has and make it better. That is always good enough to win."

Assessing offensive line's progress in 2017

The Vikings have been **shuffling their offensive line** combinations during training camp and the preseason in an effort to find the best starting five before the regular-season kicks off on Sept. 11.

A number of new faces are in the position group after last year's unit was hit with a barrage of injuries and forced to shuffle midseason. *Chicago Tribune *reporter Brad Biggs **delved into Minnesota’s offensive line** that last season utilized eight different starting combinations. He wrote:

The Vikings defense, which ranked third in yards, sixth in points and sixth in sacks per pass attempt in 2016, is going to be very good again, one of the best in the league. But if the Vikings are going to challenge for the NFC North crown and push for a playoff berth in a year when Super Bowl LII will be at U.S. Bank Stadium, it's going to be because they are much healthier and much better along the offensive line.

Biggs mentioned the drafting of Pat Elflein, who has been playing primarily center but has seen a few reps at guard, as well, with Nick Easton also competing at center. He identified Alex Boone as a "veteran grinder" at the left guard position. During his visit to Vikings training camp in Mankato, Biggs observed that the offensive line has its hands full facing a top-rated defensive line daily.

The defensive line won [its] share of the 1-on-1s with Zimmer blowing the whistle after each snap. The drill favors the defense, and the Vikings are loaded on their line with Danielle Hunter and Everson Griffen coming off the edge and Linval Joseph in the middle where they also have Tom Johnson and former Packer Datone Jones.

Biggs' conclusion was that a lot rests on Minnesota's offensive tackles.

He said "the belief is the offense can be more productive in support of a top-flight defense" under the guidance of Vikings Offensive Coordinator Pat Shurmur but that a lot rests on free agent signees Riley Reiff and Mike Remmers "holding up" as the line's bookends.

Thielen ranked No. 1 on go routes

Adam Thielen fell just short of a 1,000-yard season in 2016 and this year will try to be even better than before.

Vikings fans know all about the Minnesota native, but Pro Football Focus recently tabbed Thielen as an underrated receiver. The analytics site posted a graphic to Twitter Monday morning that listed the top three receivers according to their PFF rating on go routes.

Thielen ranked No. 1 overall with a rating of 142.8, followed by Oakland's Amari Cooper (137.2) and New Orleans' Michael Thomas (131.3).

PFF specified that there were 39 receivers "with 15 targets including routes that end with a vertical break."