When it comes to the NFL, the off-field developments are as intriguing as what happens on the field lately, and the latest example was the unannounced check-in on teams’ medical staffs by Drug Enforcement Administration agents.

Sunday’s operation was part of an investigation into whether teams have mishandled prescription drugs.

A lawsuit filed in May on behalf of former players says the NFL and its teams, physicians and trainers acted without regard for players’ health, with prescription painkillers and anti-inflammatories handed out to mask pain and minimize lost playing time.

At least three road teams Sunday — the Buccaneers, 49ers and Seahawks — were visited by agents.

While it remains to be seen where that investigation will lead, the coming week should bring news with regard to Minnesota Vikings running back Adrian Peterson and when he’ll be able to return to playing after pleading no contest to misdemeanor reckless assault for hitting his 4-year-old son with a wooden switch.

On Sunday, Peterson issued a statement through the players’ union saying he would not “allow the NFL to impose a new process of discipline on me, ignore the CBA, ignore the deal they agreed to with me, and behave without fairness or accountability. The process they are pushing is arbitrary, inconsistent, and contrary to what they agreed to do.”

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