Three of the four rookies involved in curiously timed trades have now been cut, prompting the NFL players' union to continue looking into whether the deals were made to avoid paying money into a special player pool, a person familiar with the situation told The Associated Press on Sunday.

The person, speaking on condition of anonymity because the union has not made the probes public, said the developments over the weekend only served to reinforce the NFL Players Association's review of last week's trades by the Washington Redskins, St. Louis Rams, Philadelphia Eagles and Arizona Cardinals.

On Monday, the Redskins sent sixth-round draft pick Dennis Morris to the Rams for a conditional, undisclosed draft pick. On the same day, St. Louis sent fifth-round pick Hall Davis to Washington, also for a conditional, undisclosed pick.

Also that day, the Eagles sent Charles Scott to the Cardinals for Jorrick Calvin in an exchange of rookie sixth-round selections.

At the time the trades were made, Redskins coach Mike Shanahan said the deals were made because Morris was wasn't going to make Washington's 53-man roster. He then cut Davis after one practice.

On Saturday, the Rams released Morris, and the Cardinals let go of Scott, both before the 6 p.m. NFL deadline to set a 53-man roster. Calvin, with the Eagles, was the only one of the four to make a team.

Under collective bargaining agreement rules for an uncapped year, if a drafted rookie is cut by the team that drafted him, that team is required to pay 85 percent of that player's salary into a rookie pool. The money from that pool will be distributed to rookies early next year based on the number of downs played in the 2010 season.

The way the rule is written, teams could circumvent the payment by trading a drafted player they were going to cut to another team — and have that team cut the player. Even so, the amount of savings would be small by NFL standards: just $263,500 on a first-year minimum salary of $310,000, the standard pay this year for low-round draft picks.

It is unclear what outcome the union might seek if the trades are found to be a way to skirt the payments, although it would be likely that the union would want all the teams involved to make the payments as if they had cut the players themselves.