Members of the National Football League players union wondered yesterday whether they would end their two-week-old strike and return to work without a new contract after union chief Gene Upshaw said he would agree to that, "if that's what the players wanted."

His remark left Jack Donlan, chief negotiator for the league's 28 club owners, uncertain, too. Asked to speculate on whether the strike would soon end or whether the two sides would return to bargaining, Donlan said: "I think we'll know a lot more by the middle of the week." He was certain of one thing, though: the owners want a contract that goes beyond three years.

With 86 union players having crossed the picket lines and returned to their teams for today's full slate of replacement games and many more indicating they are frustrated by this 13-day-old strike, Upshaw was asked if the union would have to reconsider its position.

"We have 1,520 players out on strike," he told United Press International. "Over 95 percent of the players are still on strike . . . Before I would see the strength of that group eroded I would consider going back without an agreement, if that's what the players wanted.

"If they decide at some point in time {to vote to return without a contract}, it's up to them."

But Doug Allen, assistant executive director of the union, said yesterday: "Going back to work without a contract is not under consideration." But St. Louis Cardinals player Stump Mitchell said Upshaw had left him with that impression after a meeting Friday.

Mitchell told the St. Louis Post-Dispatch: "Gene said he wasn't going to allow us to lose much more money. He doesn't want to see us hurt."

Allen countered: "What Gene was saying to the Cardinals and what he has said all along is, 'Hey, you guys are the ones who decide.' But going back without a contract is not something that's going to happen tomorrow or in the immediate future. To listen to what was coming out of St. Louis, the strike was over. Is the strike over? Hell, no. We've got the support of 95 percent of the membership."

Allen said that going back to work without a contract would have to be approved by the union's executive committee and its board of representatives, "and that is not under consideration." Upshaw could not be reached for comment subsequently because he was traveling to his grandmother's funeral in Texas.

But there were indications support for the strike is less than 95 percent. Besides the 86 players who returned, as many as 10 San Francisco 49ers were prepared to go to work before changing their minds following a meeting with Coach Bill Walsh. And Los Angeles Raiders managing partner Al Davis had to intervene to prevent four players from crossing that team's picket line. "I didn't think very much of that," Donlan said.

In addition, the Chicago Bears have announced they will hold a news conference today or Monday, amid speculation that the entire team is ready to end its walkout. Several of the Bears were apparently upset at Upshaw's comments on Thursday that the league owners refuse to negotiate fairly with the union because he is black.

Mike Singletary, the Chicago union representative who is also black, said, "I see no evidence this is a black-versus-white issue. I don't want to see this sink into the gutter."

The Management Council was counting on such defections. "Obviously, I anticipated the pressures building on the players, and I think the pressure will build some more," Donlan said.

Another management source said, "We've said all along that free agency {the sticking point of these negotiations} is not a players' issue but the union issue, and I think this shows that."

Donlan, referring to the union's conflicting statements, said, "Maybe we can find out now what the union's real agenda is, if they can figure it out. Maybe Gene and Doug and those guys can get together and figure out what they want."

Donlan also said that new issues have arisen since the beginning of these negotiations in April. About the only thing the two sides agreed on was the length of the new collective bargaining agreement: three years. But because of the second regular season strike in five years, Donlan said, "there isn't an owner in the league who wants to sign an agreement and go through this again in little more than two years. Not one. The fans won't stand for it either."

Donlan indicated the owners will now push for a five-year contract.

Meanwhile, 14 games will be played today and Monday despite the return of more than 300,000 tickets -- more than one-third of the total originally sold for those games.

An NFL official said that the three networks have submitted a payment of nearly $100 million to the league, which will be distributed to the clubs.