Vikings' Adrian Peterson: Running on underwater treadmill

Peterson (knee) has progressed to the point that he's running on an underwater treadmill, Ian Rapoport of NFL Network reports.

Analysis:

Typically, a repair on a torn lateral meniscus is accompanied by a 3-to-4 month recovery timetable. If his incredible healing powers coincide with a return on the early end, Peterson's rehab will be complete just two days before a road test against the Packers on Christmas Eve. He has a number of hurdles to surpass, though. At the moment, he's running on 30 percent of his weight on a submerged treadmill, which he'll slowly but surely increase. Once he approaches his body weight in that realm, he'll proceed to running in normal conditions in order to see how his right knee reacts. If there are any setbacks, the Vikings will scale back Peterson's workload. Otherwise, he'll set his sights on a return in Week 16 or 17.