2015 Minnesota Vikings training camp preview

The Minnesota Vikings open training camp on July 26 at Minnesota State University in Mankato, Minnesota. Here's a closer look at the Vikings' camp, which wraps up on Aug. 13.

Top storyline: After returning to the Vikings on June 2 and ending an 8½-month absence from the team, Adrian Peterson is getting ready for his ninth NFL season with plenty to prove. The running back turned 30 in March, but said in February he planned to "shock the world" in his return from last year's suspension, and the Vikings are banking on a big year from Peterson. He's scheduled to make $12.75 million this season and will be a featured piece of the offense after playing just one game last season. Peterson likely won't play in the preseason, but seemed to be caught up on the Vikings' offense during organized team activities and minicamp in June. Training camp will bring his first work in pads in more than nine months.

Position battles to watch: The most pivotal spot -- and possibly the most competitive -- will be right guard, where the Vikings are looking for a new starter after moving Brandon Fusco to the left side. Rookies T.J. Clemmings and Tyrus Thompson could get chances to start after playing tackle in college, as could guard David Yankey. The Vikings might also turn to veteran Joe Berger, who filled in capably at both guard spots last year when the Vikings called on him because of injuries.

Veterans to watch: Left tackle Matt Kalil needs to have a better 2015 season after injuries marred his performance in 2014. The Vikings picked up Kalil's fifth-year option in May, but could always release the fourth overall pick in the 2012 draft if he doesn't prove worthy of earning more than $11 million next year. Linebacker Chad Greenway is back for his 10th season after restructuring his contract this spring; he figures to start on the weak side, but could have to battle for playing time in the nickel package. Defensive end Brian Robison, who turned 32 in April, is returning from a May pectoral injury that caused him to miss most of the Vikings' offseason program.

Rookies to watch: Second-round pick Eric Kendricks is the favorite to start at middle linebacker after an impressive minicamp, and could wind up as a three-down linebacker if the Vikings feel comfortable with him in their nickel package. Either Clemmings or Thompson could win the right guard spot. And while the Vikings will be patient with first-round pick Trae Waynes, the former Michigan State corner might see more opportunities with Josh Robinson recovering from a partially torn pectoral muscle.

Bubble watch: Robinson hasn't put it all together in three NFL seasons, and now that he's in danger of missing part of the season with his pectoral injury, the Vikings will likely put him on the physically unable to perform list to start camp. They could eventually decide to move on from the 2012 third-round pick. Safety Robert Blanton started next to Harrison Smith most of last year, but will have to earn the top job for a second year, against competition from young players like Antone Exum and undrafted free agent Anthony Harris.

Golden camp: While the NFL season will end with a 50th anniversary celebration at the Super Bowl, the Vikings will be commemorating their own golden anniversary at the start of the year. They're spending their 50th training camp at Minnesota State, and will mark the occasion with a number of different events throughout training camp. Fans making the trek to Mankato might want to check out the Blue Earth County Historical Society's exhibit on 50 years of Vikings training camp, which runs through Sept. 4.

For daily updates at camp, check out the Minnesota Vikings clubhouse page