Washington Redskins center Jeff Bostic, his right knee still in a brace to protect the ligaments he tore last October, said yesterday during the first day of the team's minicamp that he doesn't expect to be able to play again until October, at least five games into the 1985 season.

"It's coming along real good, but October is about what I'm guessing," he said. "It will be like the old days, when teams used to play 12 games. I only played in eight last year. This will be an improvement."

As the Redskins' annual week-long May workout lurched into its first day of rookie physicals and drills, nothing, not even Bostic's lengthy recovery, could pop the springtime bubble.

"We'll let Jeff take his own pace," Coach Joe Gibbs said. "We have no timetable. It's whenever he can be ready. We hope it's sooner than that, but there is no definite answer."

When Bostic, the National Football Conference's starting center in the 1983 Pro Bowl, suffered extensive ligament damage in a game at St. Louis and underwent reconstructive surgery, the Redskins figured he would be out nine months to a year.

Recently, however, Gibbs said he expected Bostic could be back late in this summer's training camp.

Bostic's response? He smiled, eyed his purple 8 1/2-inch scar and shook his head.

"That would be the earliest date," he said. "I would expect to be working out during training camp, but not practicing."

Rick Donnalley, Bostic's replacement last season, is expected to fill the void again. General Manager Bobby Beathard said the Redskins would like to obtain another center as Donnalley's backup, but, he added quickly, "I don't know where we'd find him."

Hide-and-seek began on the steamy practice field yesterday. It's possible tackle Mike McClearn, an emigre from the U.S. Football League's Philadelphia/Baltimore Stars, or guard Raleigh McKenzie, an 11th-round draftee from Tennessee, might also work at center.

The offensive line has by no means cornered the market on experimentation. The Redskins gained two wide receivers yesterday when they moved reserve cornerback Ricky Smith to make room for top draft pick Tory Nixon, then signed wide receiver Gary Clark of James Madison University, the Jacksonville Bulls' leading receiver last season, to a two-year contract.

Clark and his six-figure salary got caught in a financial vise in Jacksonville and the Bulls released him last month.

"They came out and told me the only reason I was gone was the team's financial situation," said Clark, who caught 56 passes for 760 yards and two touchdowns last season. He also returned punts and kickoffs in the USFL and is expected to compete with Redskins return man Mike Nelms in training camp.

Had Clark not signed with the Bulls in January 1984, the Redskins might have drafted him last year, Beathard said. Indeed, the Redskins did take him in the second round of the supplemental draft of USFL players last year.

"He was good at James Madison and got even better in the pros," Beathard said.

Smith, obtained in a trade with New England last fall, played wide receiver with the Patriots.

"We are just taking a look at him there," said assistant head coach Richie Petitbon. "Now that we got (Nixon) in the draft, Smith's best opportunity will be to play on offense."

It may not be a particularly good one. At best, Smith joins a logjam of other receivers, but he seems undaunted. "This is better for me," he said.

Nixon, the 33rd player selected in the National Football League draft, is unsigned, yet he accomplished something the Redskins' last two top draft picks were unable to do. He made it to the first day of minicamp.

Last year, defensive tackle Bob Slater missed the first day because of a mix-up with his agent. Two years ago, cornerback Darrell Green had a test at college.

Nixon's final exams at San Diego State are next week. "I have three on Monday," he said. "I brought all my books to study at the Marriott."

On draft day, the USFL's Tampa Bay Bandits professed their interest in Nixon. Two weeks later, it appears to have cooled.

"We haven't been in contact with his agent (Larry Muno)," said Tim Ruskell, Tampa Bay's director of scouting. The Bandits have their eye on cornerback Derrick Burroughs, a first-round choice of the Buffalo Bills.

Nixon said: "I'd be very disappointed if it didn't work out here."

This barely is an issue with Beathard.

"We'll get him," he said.

The USFL figures prominently at one more Redskins position: kicker. Although he and the other veterans don't have to report until Wednesday for their physicals, Mark Moseley was kicking and retrieving footballs by himself before the rookies, some younger veterans and new running back George Rogers -- 66 players in all -- took the field for their early evening workout.

The Redskins could give Moseley some competition this summer. They made Tony Zendejas of the Los Angeles Express their first choice in the '84 supplemental draft and now would like to sign him.

Zendejas' contract expires when the '85 USFL season ends. The Redskins already have scouted him.

"We'll wait until the end of their season to see what develops," Beathard said. "He would be an important guy for us to get."

Clark (5 feet 9, 173 pounds) was among eight free agents signed by the Redskins yesterday. The others: linebackers Keith Biggers (6-0, 210) of Southern California and Bob Knapton (6-2, 225) of Northern Colorado; safety Napoleon DuBois (6-1, 183) of Richmond; running back Gene Lake (5-10, 215) of Delaware State; center/guard Chris Osswald (6-4, 268) of Wisconsin, and cornerbacks J.C. Pearson (5-11, 183) of Washington and Kevin Williams (5-9, 169) of Iowa State. That brings the roster to 113 players . . . Gibbs said Rogers, obtained in a trade last month with New Orleans, passed his physical. The exam included a urinalysis, but, according to Beathard, it did not test for drugs. Rogers admitted using cocaine during his rookie season in 1981, but said he since has not used drugs. "I'm willing to be tested," he said. "I have nothing to hide."