MINNEAPOLIS -- The Minnesota Vikings begin the final -- and probably most significant -- event of their offseason program on Tuesday, when they convene at the team facility for a three-day minicamp. It will be the final team event before training camp begins in late July, and it will give coach Mike Zimmer his best barometer of where the Vikings stand before the end of the offseason.

As the Vikings get started, here are four things we're watching:

1. Barr gets started: Linebacker Anthony Barr, the Vikings' top pick in the 2014 draft, will finally get to practice with the full team after graduating from UCLA on Saturday. The Vikings plan to use him at strong-side linebacker, at least in their base defense, but it seems likely Zimmer will develop a number of different ways to use the rookie. He might try to keep those under wraps as long as he can, even into the preseason, but the Vikings clearly see Barr bringing a unique element to their pass rush. Zimmer said he plans to bring the Vikings' three late-arriving draft picks -- Barr, third-rounder Scott Crichton and fifth-round David Yankey -- along a little slowly at first, but the minicamp will provide Barr's first opportunity to show how much he can handle.

2. Safety shuffle:The Vikings have been rotating several safeties through their No. 1 defense alongside Harrison Smith, with Jamarca Sanford and Andrew Sendejo sitting out because of injuries, and it will be interesting to see if they get closer to settling on anything over the next few days. It would help to see Sanford and Sendejo on the field, though there's far too little at stake to rush anyone back. Still, the absence of both players has left open some valuable opportunities, and players like Kurt Coleman, Robert Blanton and rookie Antone Exum could get more chances to make an impression.

3. OpportuniTEs: With Norv Turner as their offensive coordinator, the Cleveland Browns lined up with two or more tight ends on 466 snaps last season -- the fourth-most in the NFL, according to ESPN Stats & Information. That means plenty of work for starter Kyle Rudolph, which we knew, but it also leaves a chance for players like Rhett Ellison and Chase Ford to carve out bigger roles. The Vikings had plenty of two-tight end sets last year -- they were 12th in the league with 369 snaps of two or more TEs -- but with John Carlson gone, Ellison and Ford can move up. Ellison's previous success as a run blocker might give him the upper hand.

4. QB derby continues: Rookie Teddy Bridgewater looked good during the Vikings' organized team activities that were open to the media, but the minicamp should offer a more complete picture of where Bridgewater is at this point, especially as he compares to veteran Matt Cassel. The Vikings might wait until training camp to decide on a starter -- or at least to announce one -- but the guess here continues to be that the job is Cassel's, unless Bridgewater is good enough to beat him out. Both players can keep making their cases this week. Christian Ponder, meanwhile, needs to turn things around after a poor set of performances during OTAs; he's talked about having leverage heading into free agency next year, but he needs to convince the Vikings not to cut their losses before then.