Adrian Peterson's absence from the Minnesota Vikings' organized team activities isn't a surprise. Given a choice, Peterson would prefer to play for a new team this season.

But don't mistake his absence for a sign that he could be traded this offseason. The only way he's going to get away from the Vikings is by retiring. Here are several reasons why a Peterson trade isn't going to happen:

1. The Vikings need Peterson to make life easier for Teddy Bridgewater. The former Louisville star showed a lot of promise as a rookie, but they need him to grow as a quarterback in his second year if the team is to make a playoff run. Peterson's presence in the backfield provides a huge help in that regard. Head coach Mike Zimmer and general manager Rick Spielman have said they have no desire to trade Peterson, and the reason why is he's the best player on their offense and can take a ton of pressure off of their sophomore QB. They won't panic just because Peterson isn't showing up at OTAs.

2. The draft was the last real opportunity for a team to get a deal done. Once the Vikings got past the second day of the NFL draft, the opportunity to deal for Peterson more or less went away. The Vikings might not have accepted a first-rounder for Peterson, but they likely would have at least listened to the offer. Once Day 2 of the draft ended, all a team could offer was a fourth-round pick or something in next year's draft (which would have less appeal for a Minnesota team looking to make the playoffs this season). Also worth noting here: Most teams that had the biggest need at running back -- the Cardinals, Chargers and Jaguars among them -- drafted a running back from one of the richest prospect crops at that position in more than a decade.

3. The Cowboys are an intriguing option -- but not a realistic one. Forget about the Cowboys dealing for Peterson. Yes, it makes football sense given the uncertainty of Dallas' running back situation, the opportunity for Peterson to run behind the Cowboys' outstanding offensive line, and his reported interest in playing for the team. But his $12.75 million salary doesn't fit in the Cowboys' salary cap. As of Tuesday, the Cowboys have $12.8 million of cap room. Unless the Vikings would give Peterson away for a low draft choice and Peterson would accept a big pay cut along with a restructured contract, the Cowboys are out of the bidding. Neither of those scenarios is very likely.

4. The price the Vikings would be looking for is too high for any potential suitors. What could the Vikings get for Peterson if they wanted to trade him? At best, the Vikings would be looking at maybe a fourth-round choice that could be upgraded to a third or a second based on his performance. That's far from true value for a Hall of Fame-caliber running back. As mentioned earlier, not even a first-rounder would for certain cause the Vikings to trade away Peterson.

Why would teams offer so little? The trade market has changed significantly since the new collective bargaining agreement went into effect in 2011. The new CBA enhanced the value of getting starters out of the draft and de-emphasized the value of players in their 30s. The only time since 2011 a 30-plus-year-old player has been traded for anything higher than a fourth-round choice was in 2011 when the Raiders dealt for Carson Palmer.

In 2014, not a single player netted anything higher than a fourth-round choice in a trade. Jimmy Graham and Kenny Stills generated more than that in trades this offseason (a first for Graham, a third for Stills), but those guys are in their 20s. Peterson isn't typical of a player to hit the trade market, but he isn't a young player heading into his prime, either.

Bottom line: The only way Peterson isn't playing for the Vikings this fall is if he chooses to retire -- something he has considered, according to what he told ESPN.com's Ben Goessling. But retiring would be forgoing a huge payday when the season starts, and the conditions simply aren't right for him to move in a trade.