Adrian Peterson's standoff with the Vikings seemed as if it might stretch into training camp after his Twitter rant last week decrying the NFL's lack of guaranteed contracts. But Peterson surprisingly decided Monday to rejoin his teammates after conversations over the weekend, specifically with second-year coach Mike Zimmer.

The standout running back returned to the Twin Cities on Monday night and participated in the team's organized team activities on Tuesday morning at Winter Park. It was the first time he has practiced with his teammates since being exiled from the NFL last September.

Peterson joined Zimmer for a news conference, during which he carefully and thoughtfully expressed remorse for injuring his young son a year ago, insisted he was happy to still be a member of the Vikings and explained why he abruptly decided it was in his best interest to report to Winter Park on Tuesday.

"I had a long time to really think about things and ultimately what it came down to was getting back in the building," Peterson said. "I've been working out hard, been keeping my body in shape. And it came down to getting back in the building, being around my teammates, being around the coaches."

Peterson admitted that earlier this offseason, he was unsure if returning to Minnesota would be best for his family and him.

"At that time, I really didn't know what I wanted," Peterson said. "I really didn't know if I wanted to play somewhere else, if I wanted to retire. I didn't know if I wanted to get into track and do something different."

Peterson was then asked if it were up to him would he prefer to be on another team.

"No. I'm happy with where I'm at here with the Minnesota Vikings," Peterson said. "I love the coaching staff. … We have a young team, hungry team, excellent young quarterback who has a year under his belt now and we have a lot of talent. We can accomplish great things."

Since January, the Vikings publicly maintained they had no plans to release or trade Peterson.

Peterson has three years left on the contract he signed in 2011 and is slated to earn roughly $45 million between now and the time it expires in 2017. He is due a $12.75 million salary in 2015. But there is no more guaranteed money in his contract, meaning he could be cut at any time.

In his Twitter comments Thursday, Peterson hinted that he wanted guaranteed money beyond this season. Agreeing to redo his deal could help the Vikings avoid another contentious offseason in 2016. But Peterson's return comes with no assurances that the Vikings would rework the contract, a league source confirmed.

Coach's influence

Peterson was the only Vikings player not in attendance last week for the start of OTAs. That prompted Zimmer to tell reporters, "He can play for us, or he can not play."

Zimmer's comments, sparked by several questions from reporters about Peterson's absence from OTAs, restarted the conversations between Peterson and Zimmer, a coach who has earned deep respect from Peterson despite the player's extended absence. Their talks continued until Peterson chose Monday to come back to Winter Park.

"This guy is a Hall of Fame player, he's not just a guy to come in off the street, this guy is really, really special and I love his heart and his competitiveness, the way he wants to win," Zimmer said.

How much did Zimmer's influence factor into Peterson being in the building?

"A lot. Maybe more so than he knows," Peterson said. "He's just one of those guys, one of those coaches, that you really don't want to disappoint, because you understand, you're able to see that he has the same passion for the game as you. And he's going to do the right thing."

Apologized to his son

Peterson's return likely ends a turbulent nine-month span for the running back.

Peterson played just one game, the season opener, during the 2014 season after a Texas grand jury indicted him last September on a felony charge for whipping his then-4-year-old son with a switch.

He was soon placed on the commissioner's exempt list. Then, after pleading no contest to a misdemeanor charge of reckless assault on Nov. 4, he was moved to the suspended list. Peterson was eventually reinstated by the NFL on April 16.

Peterson on Tuesday admitted he made a mistake with his son and said he has apologized to the boy for excessively punishing him and causing him injury. And he added that he can feel comfortable knowing that his son still loves him and wants to be around him.

A few hours earlier, Peterson flashed a wide smile as he walked out the locker room doors for the start of practice, with defensive end Brian Robison waiting for him near the fields and pretending to snap photos of Peterson with an imaginary camera.

Soon, Peterson was out on the field taking handoffs from second-year quarterback Teddy Bridgewater and playfully stiff-arming defenders as he finished off runs.

Happy to be back with his teammates, Peterson plans to continue attending voluntary workouts and to participate in the mandatory minicamp June 16-18.

"It's good to get him here with the rest of the guys, with the rest of the players," Zimmer said. "We welcome him with open arms. Unequivocally."