Pro Football Hall of Fame Game 2015: Game Info, Preview Vikings vs. Steelers

The Minnesota Vikings and Pittsburgh Steelers both have high hopes for the 2015 season, but don't expect either team to reveal much as they kick off the preseason in the Hall of Fame Game Sunday night in Canton, Ohio.

Running back Adrian Peterson returns to the Vikings in 2015 after missing 15 games last year while he was on the commissioner's exempt list. When healthy and on top of his game, Peterson is one of the most dynamic running backs in the NFL (2,097 yards in 2012), and his presence can raise the level of the Vikings offense significantly. Peterson is not expected to play in this game, according to the Star Tribune.

The Steelers finished the 2014 season on a roll, as they won their final four regular-season games thanks to their dynamic offense with quarterback Ben Roethlisberger, running back Le'Veon Bell and wide receiver Antonio Brown leading the way. None of those three players are expected to participate in this game either.

That's the problem with the preseason: The last thing coaches want is to lose a key player to injury before Week 1. Yet every player needs to log some game time in August if they are going to be in top form for the start of the season.

The Steelers open the season Sept. 10 at New England, while the Vikings will visit San Francisco on Sept. 14.

Where: Tom Benson HOF Stadium, Canton, Ohio

When: Sunday, Aug. 9 at 8 p.m. ET

TV: NBC

Betting Line (via Odds Shark): Vikings (-3.5)

Tom Dahlin/Getty Images

Both teams hope to improve significantly on defense this year, and both have taken steps to do so. Zimmer was one of the game's most respected defensive coordinators before the Vikings named him head coach prior to the 2014 season, during which his team gave up an average of 344.7 yards per game and an average of 5.4 yards per play, which were both middle-of-the-pack numbers.

The Vikings tried to address some of their defensive mediocrity through the draft, as their top three draft choices came on that side of the ball. First-round pick Trae Waynes of Michigan State has the speed and length to move into a starting position in the secondary, and the cornerback has done nothing in the early part of training camp to hurt his chances of doing just that.

"

Vikings CB Captain Munnerlyn is all in with Mike Zimmer's defense this season: http://t.co/lHkHqdYmLW pic.twitter.com/s7BCHOIqVr

— Vikings Journal (@vikingsjournal) August 3, 2015"

The Steelers struggled on defense last year, and veteran defensive coordinator Dick LeBeau has been replaced by former linebackers coach Keith Butler. The Steelers ranked 18th in yards allowed last season and struggled to make big plays. They had just 33 sacks and 11 interceptions in 2014.

George Gojkovich/Getty Images

The Steelers defense needs to get faster this season, and while they are unlikely to reveal many new wrinkles against the Vikings, there is plenty of optimism among Butler's players. 

"My expectations are going to be high," safety Will Allen told Ed Bouchette of the Pittsburgh Post-Gazette. "We’re going to be a top-five defense. We have the guys, we have the ability to do it. It’s just a matter of being disciplined, being focused and doing it."

Allen's optimism is reflective of some of the changes Butler has made on defense. In his scheme, the defensive ends will be asked to rush the quarterback with more frequency than they did in the past, and the Steelers will also play more two-deep zone.

"

Inside Slant: On defense, the Steelers have addressed a need for speed - ESPN (blog) http://t.co/jUXmT7MuZY Pittsburgh, Steelers

— NFLupNow (@NFL_up_Today) August 7, 2015"

If the Steelers can confuse opposing quarterbacks by mixing up their look in the secondary, they should find a way to come up with more interceptions this season.

Few of the defensive changes will be revealed in detail in the preseason opener, but it is likely that fans will notice at least some of the schematic differences from previous years.