Peterson, 27, is recovering from surgery for the torn anterior cruciate and medial collateral ligaments in his left knee suffered on Dec. 24 against Washington.
The Vikings and Peterson roundly have said their goal is to have him on the field for the Sept. 9 opener at Jacksonville. But he's less than seven months removed from reconstruction surgery, and placing him on active/PUP gives the Vikings flexibility in case he has a setback.
Players on active/PUP can be activated at any time. Once a player is activated, he's ineligible for reserve/PUP, which sidelines him for at least six weeks.
The Vikings expect Peterson to be ready well before that, but it could be weeks before he participates in a practice. (1500 ESPN Twin Cities)
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