The team sent letters to both players last week informing them of the decision. The action initiates a three-game suspension, which will be served after each player signs.
As restricted free agents, Jackson was tendered at $3.268 million and McNeill at $3.168 million this offseason, but they want long-term deals that the Chargers appear unwilling to give. The players didn't sign their tenders by the June 15 deadline, so they each forfeited approximately $2.5 million because the team exercised its right to lower the dollar amount.
The Seattle Seahawks confirmed Friday that they have been granted permission to negotiate with Jackson, but a league source told NFL Network insider Jason La Canfora that neither a contract agreement with the Pro Bowl wide receiver nor a trade with the Chargers is close. The Washington Redskins also have shown interest in Jackson.
Chargers assistant general manager Randy Mueller attended Saturday night's Seahawks-Green Bay Packers preseason game to scout prospects for a possible Jackson trade, the Milwaukee Journal Sentinel reported via Twitter.
The Chargers haven't shown any interest in putting McNeill on the trading block.
The Associated Press contributed to this report