The next phase of the NFL offseason is here, as mandatory minicamps start Tuesday and run through Thursday for nine NFL teams. While voluntary minicamps and rookie camps have value, these are the most important practice sessions in preparation for the 2019 season to date.

Not only do these minicamps provide a taste of what will happen when seasoned veterans combine with rookies and offseason acquisitions for the first time in a mandatory setting, they also offer a glimpse at potential problems down the road. Who doesn't show up can be more newsworthy than who does.

With that said, here are the main things to pay attention to for each of the nine teams that are practicing this week. The remaining 23 squads will take the field on June 11.

JUMP TO A TEAM:

CLE | DEN | DET | MIA | NE

NYG | NYJ | TB | WSH

How will Odell Beckham Jr. blend with his new teammates?

The Browns' new No. 1 wide receiver has attended only one voluntary offseason practice because he prefers to work out on his own in California. Mandatory minicamp represents his first extensive chance to work with quarterback Baker Mayfield. If the Browns are going to become the "new Patriots" -- as Beckham suggested to GQ -- Cleveland needs Beckham and Mayfield to build a rapport as quickly as possible. -- Jamison Hensley

play 0:22 OBJ's custom accessory on his Rolls-Royce is legendary Odell Beckham Jr. installed a mini figurine of himself and his legendary one-handed catch on the hood of his Rolls-Royce … and it's motorized.

Will Joe Flacco set the tone?

The mandatory minicamp will close out the Broncos' offseason work, and thus far, Flacco has looked like the steady veteran starter the Broncos had hoped for when they traded for him this offseason. But Flacco is going to hear chatter about rookie Drew Lock, the Broncos' offensive failings over the past three seasons and the number of birthdays he has had. Flacco, 34, has to give this team a little "I got this" swagger and run an offense that can attack all parts of the field. If he is locked in, Flacco can set the tone and give the Broncos momentum when they report for training camp in mid-July. -- Jeff Legwold

What does the new offense look like?

New offensive coordinator Darrell Bevell has made it clear he wants to run the ball and that he has asked Matthew Stafford to do different things than he has done in the past. What those are, he wouldn't say. But this will be the first extended look at the offense, so it can start to paint a picture of what it will look like and how different it'll be from the Jim Bob Cooter-based offense that Stafford ran previously. Who Stafford sees on defense also will be a question, as both cornerback Darius Slay and defensive tackle Damon Harrison have missed several voluntary workouts. Whether they attend minicamp will be worth paying attention to. -- Michael Rothstein

Ryan Fitzpatrick vs. Josh Rosen

The final week of the Dolphins' starting quarterback battle before summer break will give us another glimpse of how much progress Rosen has made in the team's new offense. He has spent a month with the team thus far, and he admitted Wednesday he still is working to handle everything Miami asks its quarterbacks to do. Meanwhile, Fitzpatrick has consistently run the starting offense and has been the best quarterback during organized team activities. The battle will heat up this summer, but a good day or two from Rosen could add more fuel to it before the break. -- Cameron Wolfe

First-round draft pick N'Keal Harry will have his first formal practice sessions with Tom Brady this week at minicamp. Bob DeChiara/USA TODAY Sports

Tom Brady returns to camp

For the second year in a row, Brady stayed away from voluntary workouts, so this will be his first chance to work with the entire team and a largely new group of tight ends and wide receivers. Brady, 41, previously said that staying away from voluntary work allowed him to fill his tank so that he is at his best personally, and for the team, when he reports to training camp. He did get some one-on-one time in with first-round draft choice N'Keal Harry, but things should shift to a higher level in mandatory camp. -- Mike Reiss

Will Daniel Jones make a move?

He already has flashed at times during OTAs. Can he continue to close the gap on starter Eli Manning? One veteran told ESPN recently that Jones has impressed but still has a "long ways to go." The No. 6 overall pick is the future of the franchise. All eyes will be on him once again. -- Jordan Raanan

Introducing Le'Veon Bell to New York

The Jets' marquee free-agent addition, who has skipped the vast majority of the voluntary workouts, is expected to attend. He has been working out on his own in South Florida, but there's bound to be significant rust, considering he hasn't participated in a team football activity since January 2018 -- a playoff game when he was on the Steelers. Bell, who will meet the New York media for the first time, will have to answer questions about his scrutinized relationship with head coach Adam Gase. -- Rich Cimini

Will Ndamukong Suh fit in?

Suh arrived in Tampa on Thursday, and he is having to quickly learn Todd Bowles' defense. He won't be tackling guys to the ground, but he can be disruptive. That would go a long way in easing concerns over Jason Pierre-Paul's injury. It's also worth watching how Suh interacts with the team. Suh has been criticized for not being a team player, and he now will be teammates with Evan Smith, who received Suh's infamous stomp in 2011. Head coach Bruce Arians isn't worried about any of that. "I hope I still see that look in his eye," Arians said. "I can handle the rest; that's easy. I just want to see that look in his eye. I'll be happy." -- Jenna Laine

The quarterback battle -- Dwayne Haskins vs. Case Keenum

It's hard to know how much of a chance Haskins has at the starting job at this point. The Redskins wanted to use the spring to gauge where he was at and if he was a serious contender. But there will be more big names around to help determine where everyone is at: tight end Jordan Reed, left tackle Trent Williams and corner Josh Norman. All have been working out elsewhere during the voluntary portions, but having them in camp will help the offense progress -- and will help show where both quarterbacks are in this system. -- John Keim