The 2012 MVP has been linked with a move away from the Minnesota Vikings, but remained with the team when the trade deadline passed earlier this week.
Walker, who joined the Vikings in a trade from the Dallas Cowboys in 1989 told the St Paul Pioneer Press: "It would be an insult. Adrian has done so much for the Vikings that, unless he asks for a trade, then that would be insulting.
"He's played his heart out. He came back from that knee injury. They can build the team back up. It was an incredible deal.
"But I don't think in today's game it could happen because there were so many players involved and the amount of players now is so important, the way the salary cap is."
Peterson has 571 rushing yards and six touchdowns in 2013.