49ers' McKinnon preparing for season with Adrian Peterson's help

Incoming San Francisco 49ers running back Jerick McKinnon hasn't taken much time to relax this offseason after signing a reported four-year, $30-million contract in free agency.

McKinnon has been preparing for the grueling workouts that begin April 16 - which head coach Kyle Shanahan says are intended to "humble" his players - under the tutelage of former teammate Adrian Peterson.

"Running hella hills," McKinnon said of the workouts, according to Matt Barrows of The Sacramento Bee. "We do a lot of hill work, track stuff, box in the offseason, work on our hands for pass (protection) and stuff like that. Basically honing in on little details."

McKinnon has worked out with Peterson in Houston every offseason since 2015. He entered the league as a third-round pick of the Minnesota Vikings in the 2014 draft.

Unsure of what's waiting for him at the 49ers facility in Santa Clara, Calif., McKinnon is excited for his first true opportunity to serve as a No. 1 back.

"I don't know what they have in store for us, but I'm pretty sure it will be some hard work and some good team bonding," he said. "Yeah, I'll be looking forward to it."