If Brian Bosworth is serious about his declaration of June 12 -- that he will never play for the Seattle Seahawks, the team that selected him in the supplemental draft -- he may have to deal with the lonely existence of the NFL holdout.

Worse things, of course, have befallen football players, including the ambitious linebacker with the spiky haircut who is no longer welcome at the University of Oklahoma and who hopes Seattle will trade his rights to one of four NFL teams. But barring a trade and barring Bosworth's changing his mind about Seattle, his only option is to sit out a year.

Holding out can be costly and risky, as well as a tactic capable of producing psychological pressure and lingering resentment. On the other hand, it can also pay off big financially.

Holding out is a relatively infrequent phenomenon in professional football, as might be expected in a sport in which the average career lasts less than five years. The relatively few players who have held out have been mostly veterans trying to renegotiate contracts, not rookies such as Bosworth, holding out for a trade.

There have been at least two players in the last decade who have sat out a year after college for contractual reasons.

Punter Tom Skladany of Ohio State was Cleveland's No. 2 selection in the 1977 draft, but he sat out the entire season and never kicked for the Browns.

In his delayed rookie season of 1978, Skladany, having been traded to Detroit, benefited from kicking in the Pontiac Silverdome rather than in the unpredictable winds rolling in off Lake Erie and led the NFC with a 42.5-yard average. In 1981, he had the league's best net average.

But Skladany sat out another training camp in 1983, shortly before he joined Philadelphia as a free agent. Skladany lasted one month with the Eagles before the erratic distances and inferior hang times of his punts cost him his job and his career.

Eagles center Matt Darwin is another player who sat out a year after college. He was drafted by Dallas in the fifth round in 1985, out of Texas A&M, but couldn't come to terms with the Cowboys. He thus was eligible for the 1986 draft, and the Eagles took him in the fourth round with one of the picks they had acquired from the Rams for defensive end Dennis Harrison.

Last season, Darwin started 10 games after replacing Gerry Feehery, who suffered a knee injury against the Giants. Darwin made the UPI, Pro Football Writers of America, and Football Digest all-rookie teams.

Roger Staubach, the five-time all-NFL quarterback for the Dallas Cowboys, and Joe Bellino, a running back for the Boston Patriots of the American Football League from 1965 to 1967, both graduated from the Naval Academy and spent time away from the game before turning pro.

Staubach and Bellino, both of whom won the Heisman Trophy, were committed to active military duty and had no contractual problems with NFL teams. But their cases might be the two most memorable ones of star college players sitting out for extended periods before playing in the pros.

Staubach was drafted by Dallas in 1964, but he didn't join the Cowboys until 1969. He went on to spend 10 years with the team and led it to four Super Bowls and two NFL titles.

Bellino, the 1960 Heisman winner, didn't sign with the Patriots until 1965. He played three undistinguished seasons for Boston and retired.

Most of the other serious holdouts over the years have been veterans, many of whom were hurt by the inactivity.

For instance, Sam Cunningham, a running back for New England and the older brother of Eagles quarterback Randall Cunningham, led the Patriots in rushing six times in seven seasons through 1979. He sat out the 1980 season and probably suffered a shortened career as a result.

Returning to the active roster in 1981, Cunningham gained 269 yards on 86 carries, an average of 3.1 yards, and scored only four touchdowns. His longest run from scrimmage was 12 yards. A year later, he rushed for only 21 yards on nine carries in his swan-song season in the league.

Franco Harris, a 13-year pro who was the mainstay of Pittsburgh's four Super Bowl championship teams, virtually ended his superb career on a crass note in 1984 when he rejected a $600,000 one-year offer from the club, held out through training camp and was waived.

At the time, Harris needed only 363 yards to equal the NFL's all-time rushing mark, then held by Jim Brown.

Harris was picked up by Seattle for a brief stint that saw him average 2.5 yards per carry before he was released at the end of October. The holdout cost him thousands of dollars and considerable esteem, since the majority of fans, including those who once cheered him as members of "Franco's Italian Army," sided with management.