The Vikings could acquire Donovan McNabb in a trade today from Washington but that doesn't mean he would be on the field at 3 p.m. Monday when the team goes through its first practice.

According to an e-mail from an NFL spokesman, if a veteran player is acquired via trade and his contract is re-worked, he cannot practice with his new team until Aug. 4. That would mean he would miss four practices, including a walk-through.

The expectation, of course, is that McNabb will have a new, short-term deal with the Vikings in place shortly after he sets foot in Winter Park. (McNabb signed a five-year, $78 million extension last season in Washington but he won't be playing for that deal in Minnesota.)

That Aug. 4 date is the one on which the NFL Players Association is expected to recertify as a union.

While the signing of veteran free agents can't be officially announced until Friday night, the same does not hold true for trades. Trading was allowed as of 9 a.m. on Tuesday and a veteran player acquired via a trade can be brought in immediately by the new team for a physical.

Weddle off market: The San Diego Chargers have agreed to terms with Eric Weddle, meaning the safety will return to the Chargers after exploring the market on Tuesday. Weddle's agent, David Canter, had discussions with the Vikings but they were believed to be casual and Canter tweeted today that Weddle is now the highest-paid safety in NFL history. Weddle reportedly will receive $40 million over five years. He gets a $13 million signing bonus and $19 million in guarantees. In other words, Weddle wasn't going to land in Minnesota.