No sooner had the expansion Tampa Bay Buccaneers achieved perfect imperfection in their first National Football League season a year ago with an 0-14 performance than head coach John McKay boldly proclaimed:

"We will be back. Maybe not in this century, but we will be back And we will be a better football team."

In spite of some speculation to the contrary, the Bucs did, indeed, return for the 1977 season. But any resembalance between the 1976 team and this year's can be detected only in the standings. Of the 45 players on the roster, 21 were not with the club last year. And of those 21, 10 are rookies. While the Bucs are better, as the 54-year-old McKay promised, they are better only to the degree that instead of getting beaten by three touchdowns, it's only one or two.

Going into Sunday's game with the Washington Redskins in Tampa Stadium, the team has played 17 consecutive regular season weekends without a win. Another loss Sunday and the Bucs will tie the 1972-73 Houston Oilers for the third-longest losing streak in league history.

McKay, who won four national collegiate championships in 16 seasons at the University of Southern California before leaving fame for fortune in the NFL, refuses to be discouraged by this record.

"We are building a team in what we think is the best possible way, with young players," said McKay. "Right now, we physically can play with just about anybody in the league. But experience counts an awful lot in this league and that's something we don't have.

"The only discouraging thing is to lose people I know make us a better football team. We are just not good enough yet to lose first-line people and expect to be able to play with people like Dallas and Washington."

Last season, the Buccaneers put 17 players on injured reserve, including first and second-round draft choices Lee Roy Selmon and Dewey Selmon. This season, the team has already lost six players to injured reserve, including former Philadelphia Eagle quarterback Mike Boryla and veteran tight end Bob Moore. Boryla was the No. 1 quarterback until he injured a knee in the third week of the preseason.

That put the quarterbacking chores in the hands of former Chicago Bear Gary Huff. But the next week, Huff, too, went out with a knee injury and did not return until last week.

With both veterans out, that left second-year man Parnell Dickinson, who was later waived, and rookie Randy Hedberg to lead the Bucs into the regular season.

Hedberg, an eigth-round draft choice out of Minot (N.D.) State, had an impressive debut. In his first series in a preseason game against Buffalo, he lofted a 66-yard touchdown pass and the next weekend against Baltimore he passed for another touchdown as the Bucs upset the Colts, 14-0.

"Why Not Minot?" became the rallying cry for the Bucs' victory-starved fans, but against Philadelphia and Minnesota. Hedberg's inexperience showed in 13-3 and 9-3 losses.

In addition to injuries to his quarterbacks, McKay has had problems with an offensive line that has been entirely revamped from a year ago, except for former Redskin center Dan Ryczek.

"It's kind of sad when we run our famous pitch play that's designed to get eight yards and doesn't get anything," McKay says of his offense. "I love to see the ball move.I'd do anything to see that ball move more. I'd even cheat if I thought I could get away with it!"

But the ball has not moved much more this year than it did last, when the Bucs were the worst offensive team in the league. Former UCS tailback Anthony Davis, who purchased the remainder of his Canadian Football League contract so he could play with McKay and the Bucs, has not been able to break loose. And this year's No. 1 draft choice. Ricky Bell of USC, has been bothered by a bone chip in his right ankle and in last week's 23-7 loss to Dallas, suffered a bruised shoulder that may keep him out of the game with Washington.

Only the defense, under the tutelage of the venerable Abe Gibron, has been a source of pleasure for McKay.