There aren't a ton of opportunities for rookies trying to break in with the Vikings, but there are small tunnels of light as the team holds its rookie minicamp this weekend. The Vikings' draft picks, 10 undrafted signees and a host of undrafted, unsigned players on tryouts will report Friday to TCO Performance Center to begin their pro careers.

Look beyond a freshly spackled offensive line, new tight end and running back, and you can see some more openings to compete for Week 1 roles.

Rick Spielman, in his eighth draft as general manager, used his first four picks on offensive players, the first time that's happened with the Vikings in 54 years. There might not be a starting job available on defense, where newcomers will need to earn snaps as backups and on special teams.

"We don't have a lot of defensive needs from a starter position," Spielman said. "We wanted to add depth in the other rounds and we have some pretty good depth even from last year's draft. I'm excited to see some of these guys and the opportunity they're going to get."

Most opportunities will come on offense, specifically for center Garrett Bradbury, tight end Irv Smith Jr. and running back Alexander Mattison. Bradbury, at least, is expected to start among those top three picks while the other two may be featured weekly. Guard Dru Samia is likely an option behind Josh Kline at right guard.

That's the obvious part. So, where else can competition heat up this summer?

Below are five under-the-radar positions in which new Vikings could find opportunity.

Backup quarterback: The fact the Vikings guaranteed $140,000 to sign undrafted University of Washington QB Jake Browning says plenty about competition behind Kirk Cousins. It's open for business. Former Rams quarterback Sean Mannion signed a one-year deal with only $90,000 guaranteed. Kyle Sloter, the longest-tenured Vikings quarterback in his third season, has yet to throw an NFL pass after serving as the No. 3 last season. Three quarterbacks will likely be competing for two spots come September.

No. 3 (and 4 and 5) receiver: The Vikings did not exercise an expensive fifth-year option for 2020 on receiver Laquon Treadwell, their 2016 first-round pick. This changes nothing in the outlook for the No. 3 receiver job and depth, which is relatively open. Chad Beebe and Brandon Zylstra will have a leg up entering their second NFL seasons, but ex-Broncos receiver Jordan Taylor and draftees Dillon Mitchell and Olabisi Johnson are newcomers to watch.

Defensive line: A defensive lineman wasn't added until the sixth round in Armon Watts, a 6-5 defensive tackle from Arkansas. The Vikings left draft weekend with an intriguing competition for snaps behind Linval Joseph and Shamar Stephen. Watts joins the mix for depth with Jaleel Johnson and Jalyn Holmes, who also played end as a rookie last season. At end, Tashawn Bower was still in a walking boot as of last month. Five other ends, including Ade Aruna, will get chances this summer.

Cornerback: Even if Mike Hughes is ready for Week 1, the Vikings will still look for a newcomer or two for depth and kick/punt coverage this season. Holton Hill will serve a four-game suspension to start the season. So players like seventh-round pick Kris Boyd (Texas) and AAF signing Duke Thomas are positioned well if they can prove themselves in coverage and on special teams.

Punt returner/long snapper: Since the Vikings moved on from Marcus Sherels (now with New Orleans), they will need a new punt returner for the first time in nearly a decade. Running back Ameer Abdullah and Zylstra will try their hands, but both seventh-round receivers, Mitchell and Johnson, handled those duties in college and might also be candidates. If/when Austin Cutting (Air Force) resolves his plan to pursue both military and NFL careers, he will compete with incumbent Kevin McDermott for the long snapper job.