It’s still not clear if owner Daniel Snyder, General Manager Bruce Allen and the Redskins will mount another legal challenge in the salary cap case (Ray Saunders/The Washington Post)

The NFL Players Association is willing to take joint legal action with the Washington Redskins against the league aimed at retrieving some of the salary cap space that the team lost last year when it was penalized by the NFL, two people familiar with the situation said Saturday.

But the union and the Redskins have not discussed such an effort, the two people said, speaking on the condition of anonymity because of the sensitivity of the topic. According to one of those people, the Redskins are not interested in such joint legal action because they do not support the union’s allegation that the league and teams improperly colluded to restrict players’ salaries in the sport’s season without a salary cap in 2010.

Legal action by the Redskins over their salary cap reduction, without the union, remains a possibility, that person said, without indicating whether Tuesday’s opening of the NFL free agent market is a deadline for the team to take such a step. But it’s not clear what the team will do.

The new developments in the salary cap case come amid indications that the hopes of Redskins officials of recouping any of their lost cap space have dimmed in recent days.

The unrestricted free agent market opens at 4 p.m. Tuesday and the Redskins must be under the salary cap by then. They were an estimated $3 million above the cap before completing deals Saturday with tight end Logan Paulsen, fullback Darrel Young and linebacker Rob Jackson. NFL teams were permitted to begin negotiating Saturday with unrestricted free agents from other teams but signings of those players cannot commence until Tuesday.

According to one person with knowledge of the union’s thinking, the NFLPA would continue to welcome a joint legal effort with the Redskins on the salary cap case.

“The real question is why [the Redskins] didn’t seek to join in some action by the players,” the person said. “After all, the players’ theory is that [the Redskins] didn’t violate the rules and were punished for not agreeing to the conspiracy…. I’m a bit at a loss why they wouldn’t. At the very least, if you were [the Redskins], wouldn’t you cooperate with the players’ case?”

The person said there had been no dialogue between the union and the team on the subject but the Redskins still could join the union’s appeal of its collusion case against the league and teams.

The other person familiar with the situation confirmed that the union would be interested in joint legal action with the team but said the Redskins haven’t given that serious consideration because they “don’t think there was collusion.”

The Redskins are to absorb the remaining $18 million of their salary cap penalty this year. They were given a $36 million cap reduction over two years by the NFL last March, with the consent of the union, for the way in which they structured players’ contracts during the uncapped year. The Redskins and Dallas Cowboys, who were given a $10 million cap reduction over two years by the NFL, took the matter to arbitration last year but had their case dismissed.

The union filed a collusion case in federal court in Minnesota last year accusing the league and teams of operating with a secret salary cap in the uncapped year. A federal judge twice sided with the league and ruled the union waived its right to make such a claim and the case cannot move forward. The union is appealing.

One person who had been in contact with the Redskins in recent days said that team officials indicated there had been a setback late in the week in their efforts in the salary cap case. It was not clear what the setback was. But if the Redskins are unable to regain salary cap space, they would have to make moves to get under the cap and would be limited in what they could do in free agency.

There have been “many discussions over the past year” between the NFL and the Redskins regarding the salary cap case, a person familiar with the league’s position on the matter said. But as of Friday night the team had not delivered a direct threat to the league in recent weeks about going to court, the person said. That person said the Redskins’ salary cap reduction remains in place and the league has no intention of budging on the penalty.