It was that kind of weekend for the Tigers, who are now in danger of sliding out of the postseason altogether.

Monday's 4-2 defeat capped off a clinical sweep at the hands of No. 4 Florida State and could lead to Clemson needing help to even reach the ACC tournament in two weeks.

"We just have to keep trying to believe we have a chance," coach Jack Leggett said. "We have to try to sneak into the tournament, but we have to win some ball games."

Leggett was referring to the NCAA tourney, but they invariably have to make the conference one first.

Clemson (24-23-1, 10-16-1 ACC) suffered its second conference sweep at Doug Kingsmore Stadium this season after having just one in Leggett's previous 14 seasons -- coincidentally, against FSU (40-7, 22-5) in 2002.

The sweep also ensured the Tigers of their first losing conference record since 1972.

In the race for the eight-team ACC's tourney's final two spots, they remained just percentage points ahead of Duke (8-14-1) for seventh place, with Wake Forest (8-15) a half-game back in ninth.

The best-case scenario for Clemson would seemingly be for either Duke or Wake Forest to sweep the other later this week, as both teams then travel to opponents at the bottom of their respective divisions for their final weekend series -- Duke at Virginia Tech (4-20), Wake Forest at Boston College (8-19).

The Tigers conclude conference play with next weekend's series at Georgia Tech 33-14, 12-12), but they might have to wait another week to know their postseason fate.

"We have to keep fighting," shortstop Stan Widmann said. "That's been the whole thing for several weeks now."

FSU (40-7, 22-5) clinched the Atlantic Division title with Monday's win, the latest in Clemson's season-long chain of offensive struggles.

Stellar relief pitching from left-handers Casey Harman and Ryan Hinson kept the Tigers within striking distance, but they could do nothing with it.

They stranded a runner at second in five of the first seven innings and were 1-for-8 with runners in scoring position until catcher Doug Hogan's two-RBI single pulled Clemson within 4-2 in the eighth.

"We need to start getting the big hits in the big situations to start getting the wins," third baseman Matt Sanders said.

Analysts believe Clemson likewise has a slim margin for error in its final five nonconference games if it hopes to sustain its streak of 21 straight NCAA tournament appearances.

That road does not appear any easier, as the Tigers return to action Wednesday at Greenville's Fluor Field against Furman (29-15), which has won six straight and nine of its last 10.

• NOTE: Widmann, a redshirt junior, was honored with Clemson's seniors during their final home series Saturday.

But he said he joined the ceremony in case he turns pro after the June draft.

Widmann plans to graduate but would attend graduate school if he opts to return next season.

"It's kind of up in the air to see how June goes," he said. " If everything works out, we'll see."