NEW YORK -- Felix Trinidad Jr. is unbeaten in 39 fights and has held a world title for almost eight years. That's impressive.

But not to William Joppy.

"I think he's a little overrated," Joppy said. "I want to show he doesn't belong in the ring with me."

Joppy, the WBA middleweight champion, will try to prevent Trinidad from winning a title in a third weight class Saturday night.

Trinidad was a 3-1 favorite in the bout at Madison Square Garden.

"The fight will end in a knockout," said Trinidad, who has 32 of them.

Roberto Duran, who in 1989 was the last former welterweight champion to win a middleweight title, thinks Trinidad has the punch to knock out a middleweight but that he not should not go looking for KO.

Duran also believes Trinidad would be mistaken not to respect the punching power of Joppy, who has 24 knockouts in a 32-1-1 record.

Duran, the former champion in four weight divisions, was stopped in the third round of a title bid against Joppy on Aug. 28, 1998. But Duran was 47 at the time and devoid of the skills that enabled him to terrorize the lightweight division for most of the 1970s.

The 28-year-old Trinidad, of Puerto Rico, is at the top of his game, but his chin is suspect. He was knocked down five times as a welterweight and twice as a super welterweight.

The middleweight limit is 160 pounds, six more than the super welterweight limit and 13 above the welterweight limit.

Can Trinidad get up if he's knocked down by a natural middleweight?

"I'm not going in there looking for a knockout," said the 30-year-old Joppy, of Silver Spring, Md. "I'm going to be smart about it. Once I feel him out and see he can't handle my strength, I'll exploit it."

The winner of the pay-per-view bout, which will start about 11:30 p.m. ET, will fight Bernard Hopkins for the undisputed middleweight championship Sept. 15 in the Garden. Hopkins retained the IBF title and won the WBC championship by outpointing Keith Holmes on April 14 in the Theater at the Garden.

Joppy won the WBA 160-pound title in 1996 and defended it twice before losing it to Julio Cesar Green on a questionable decision Aug. 23, 1997, in the Garden. He regained it by outpointing Green on Jan. 31, 1998, in Tampa, Fla., and has defended it five times.

Trinidad, managed and trained by his father, won the IBF welterweight title in 1993 and defended it 15 times. In his last defense, he added the WBC 147-pound title on a decision over Oscar De La Hoya on Sept. 18, 1999.

He won the WBA super welterweight championship on a one-sided decision over David Reid on April 3, 2000, then took the IBF 154-pound title by stopping Fernando Vargas in the 12th round on Dec. 2.

Joppy weighed in officially Friday at 158¾ pounds. Trinidad weighed 159¼.

The weigh-in was attended by IBF-WBC heavyweight champion Hasim Rahman, who is managed by Stan Hoffman and Steve Nelson, also the managers of Joppy. Rahman would not talk about who he will fight next or for whom he would fight.

A devout Muslim, he said he would make a pilgrimage to Mecca on Thursday.

Two other 12-round bouts will be on Saturday night's card.

Raul Frank of Brooklyn and Vernon Forrest of Augusta, Ga., will fight for the vacant IBF welterweight championship. The two fought for the title last Aug. 26, but the match was declared a no-contest when Frank couldn't continue because of gash on his forehead sustained from a clash of heads in the third round.

In an IBF heavyweight elimination bout, Chris Byrd, the former WBO champion from Flint, Mich., will fight Maurice Harris of Newark, N.J.