Clemson University, college football's defending national champion, will not play in a postseason bowl game, Bill Lee Atchley, the school's president, said yesterday in a prepared statement.

He did not indicate whether the action was voluntary or a result of impending probation by the Atlantic Coast Conference and the National Collegiate Athletic Association.

"Several bowl committees have continued to express interest in us . . . but unfortunately, for reasons I now plan to explain at a press conference next week, the 1982 season for us will end with the Mirage Bowl (ACC game between Clemson and Wake Forest) in Japan on Nov. 27," Atchley said in the statement.

Clemson (7-1-1) is ranked 10th in this week's Associated Press poll. The Tigers, according to bowl sources, were considered for the Orange, Cotton, Gator, Liberty, Tangerine and Bluebonnet bowls.

The Washington Post reported last week that both the ACC and the NCAA had voted to impose two years probation with sanctions on the Tigers for infractions that included recruiting violations. Atchley has been unavailable for comment since announcing that Clemson had received reports from both the ACC and NCAA. The terms of each probation were subject to appeal.

Meanwhile, the bowl picture came into better focus yesterday, with these decisions apparently having been made by bowl committees, according to bowl sources and team officials:

Orange Bowl -- The winner of the Florida State-Louisiana State game Saturday night will receive a bid to play the Big Eight champion, either Nebraska or Oklahoma. The loser of the Florida State-LSU game reportedly gets a consolation prize as West Virginia's opponent in the Gator Bowl.

Cotton Bowl -- This matchup, according to bowl sources, is second-ranked SMU versus sixth-ranked Pitt if SMU wins Saturday against Arkansas. But if Arkansas beats SMU, the Razorbacks cannot clinch the Cotton Bowl berth as Southwest Conference champion until Dec. 4, when they play Texas. A caution: If SMU wins convincingly enough Saturday, third-ranked Penn State could opt for the Cotton, instead of the Sugar, figuring SMU would pass top-ranked Georgia in the polls. Georgia is idle this week.

Fiesta Bowl -- Barring upsets, such as Washington State beating Washington and thus sending Arizona State to the Rose Bowl, the likely matchup is Arizona State against the Big Eight Conference runner-up. That way, at best, the Fiesta Bowl gets a 9-2 Nebraska team ranked in the top 10 and, at worst, an 8-3 Oklahoma team with Marcus Dupree, Division I-A's alltime leading freshman runner.

Hall of Fame -- A treat for those who like passing, with Stanford (5-5) versus Vanderbilt (6-3). But each has to win its Saturday game.

Elsewhere--Notre Dame most likely will not play in a bowl this season. North Carolina is likely to choose the Sun Bowl and play a Southwest Conference team; Iowa, if it defeats Michigan State, will be invited to the Peach Bowl; in the unlikely event that both Washington and Arizona State lose and UCLA wins the Rose Bowl berth, Texas would be Maryland's opponent in the Aloha Bowl. Other bowls previously set are Boston College-Auburn in the Tangerine and Alabama-Illinois in the Liberty.