Rise ‘n Grind: What is Adrian Peterson doing?

BACK AND FORTH: Mike Zimmer has a knack for being blunt, and he dropped the hammer on his wayward superstar running back after OTAs on Thursday. The Vikings head coach issued an ultimatum for Peterson, saying that “he can either play for us or he cannot play.”

PETERSON RESPONDS: Peterson fired back shortly after Zimmer’s comments, telling the press that his holdout was not about trying to get traded. So what is it about? He’s just trying to secure his future with the Vikings, duh.

MORE TROUBLE FOR RAY: Ray McDonald was arrested Wednesday night for violating the restraining order stemming from his domestic violence arrest on Monday. His lawyer says he did not violate the restraining order because one was never issued.

APPEAL: Greg Hardy is appealing his 10-game suspension on Thursday.

DOUBLE DOME LAWSUITS: The efforts to build a St. Louis football stadium now have two big legal hurdles to clear. A group of state legislators are suing to stop Gov. Jay Nixon from extending the bonds from the Edward Jones Dome to pay for the new place without approval. In the city of St. Louis, the Dome authority is suing to get around a city ordinance that would require a vote for any public money used on the stadium.

PEOPLE ARE TALKING: The Chargers and San Diego reps are all set to begin stadium negotiations. The timeline will be a key issue here, at least as much as who pays for any potential new stadium.

HARD KNOCKS: It’s official, the Texans are going to be featured on the HBO/NFL Films reality show this summer. And there are plenty of things to watch with this team. Also, you don’t need HBO anymore to watch the show.

ALL CLEAR: The Navy cleared Patriots rookie long snapper Joe Cardona to play for the 2015 season.

STILL LIMITED: Sam Bradford is still being limited in his practice work with the Eagles. Could this all be part of Chip Kelly’s master plan, which is either really brilliant or diabolically insane?

READY TO GO: Bengals tight end Tyler Eifert received medical clearance for his shoulder and elbow injury.

DEMARCO WHO?: Cowboys running back Joseph Randle shared his thoughts on former teammate DeMarco Murray, saying the team’s single-season rushing record holder “left a lot of meat on the bone.”

GETTING COMFORTABLE: Marcus Mariota is looking more and more like an NFL quarterback.

DROPS: Uh oh, Lions tight end Eric Ebron had the dropsies at practice this week.

BLACK HOLE: People are buying Raiders jerseys again, lots of them.

DID YOU KNOW: Here’s something you probably didn’t know about Chiefs pass rusher Tamba Hali.