The Minnesota Vikings begin training camp as defending NFC North champions for the first time since 2009. The team still has some question marks on both sides of the ball, however. Here is a primer on position battles to watch as training camp unfolds.
Wide receiver: Who will emerge?
Stefon Diggs emerged as the top receiver during Weeks 4-8 last year, catching 25 passes for 419 yards and two touchdowns, but he caught just 31 passes for 327 yards in the Vikings' final 10 games. Charles Johnson caught 31 passes for 475 yards in 2014 but had just nine receptions in 2015. Former first-round pick Cordarrelle Patterson had only two catches in 2015, raising questions about his future with the team, while Jaruis Wright caught 34 passes for 442 yards but with no touchdowns last year. First-round pick Laquon Treadwell could become the No. 1 guy at wide receiver for the Vikings, but he will have to prove himself in training camp and the preseason. The wide receiver position appears as open as any on the Vikings roster.
Right guard: Mike Harris vs. Brandon Fusco
Fusco started 31 games at right guard for the Vikings in 2012 and 2013, earning recognition from the analytics website Pro Football Focus as one of the NFL's best right guards of 2013. The 28-year-old missed most of 2014 with a torn pectoral and played left guard in 2015. He moved back to right guard this spring after the Vikings signed left guard Alex Boone to a four-year, $26.8 million contract. Harris started every game at right guard in 2015, his first season as a starter in the NFL, and ranked as Pro Football Focus' 22nd highest-graded guard. Both Fusco and Harris appear qualified to be the starter, so this could be one of the more intriguing battles.
Right tackle: Andre Smith vs. T.J. Clemmings
Clemmings started all 16 regular-season games for the Vikings at right tackle in 2015 as a rookie but was one of the least efficient pass-blocking tackles in the NFL, according to Pro Football Focus. Smith signed a one-year deal with the Vikings in March, after starting 73 regular-season games in seven seasons with the Cincinnati Bengals. The 29-year-old had the worst season of his career in 2015, according to Pro Football Focus, and started just nine games the year before. Veteran Phil Loadholt was also in the mix for the starting job before he retired.
Center: John Sullivan vs. Joe Berger
Sullivan has been the Vikings' starting center since 2009 but missed the 2015 season with a back injury. Eleven-year NFL veteran Joe Berger started every game in his place and was named the NFL's best run blocker by Pro Football Focus. Sullivan said earlier this offseason that he is feeling great, and head coach Mike Zimmer said last month that he thought Sullivan looked completely healthy. Will that be enough for the most experienced player on the Vikings to get his starting spot back?
Safety: Who will emerge alongside Harrison Smith?
The Vikings signed Andrew Sendejo to a four-year extension this offseason, but he struggled as the predominant starter in 2015, failing to break up a pass all season, according to Pro Football Focus. The team also signed two-time Pro Bowl safety Michael Griffin, whom the Tennessee Titans cut after nine seasons. Young players Anthony Harris, Antone Exum Jr. and Jayron Kearse could also compete for the spot. The second safety spot has been a revolving door for the Vikings over the past couple seasons, so Minnesota would certainly be happy with someone taking control of the position.
Cornerback: Terence Newman vs. Trae Waynes
This may not be a position battle in training camp, but it's one to watch throughout the season. The Vikings re-signed Newman, who will be 38 in September, after he started all 16 regular-season games and led the team in interceptions in 2015. The 23-year-old Waynes played in 15 games as a rookie in 2015, a year in which the Vikings selected him 11th overall in the NFL Draft. It appears to be a matter of time before Waynes steps in as a starter, but Minnesota's oldest player appears to own the position for now.
Left defensive end: Brian Robison vs. Danielle Hunter
The 33-year-old Robison has started 79 of the Vikings' 80 regular-season games since 2011, recording 35 sacks and seven forced fumbles over that stretch. Hunter emerged in the final four games of last season, recording 3 1/2 sacks over that span and earning All-Rookie team honors from the Pro Football Writers of America. The Vikings considered Hunter raw when they drafted him in the third round in 2015, but he appears to be progressing better than expected. This also looks to be a situation where the younger player will eventually supplant the veteran.