Dan Rafael explains why Daniel Jacobs is unable to win the IBF title against Gennady Golovkin due to not participating in a weight check on Saturday morning. (1:37)

NEW YORK -- Daniel Jacobs declined to participate in the mandatory IBF weight check Saturday morning, meaning he is ineligible to win that belt when he fights unified middleweight titleholder Gennady Golovkin on Saturday night at Madison Square Garden.

"Golovkin is defending his IBF title, however, Jacobs cannot acquire the title with a victory because he did not participate in the required IBF same-day weigh-in," IBF championships chairman Lindsey Tucker said.

Golovkin (36-0, 33 KOs), who holds the IBF, WBC and WBA 160-pound world titles, participated in the weight check at a Manhattan hotel serving as the fight headquarters and weighed 169.6 pounds, just inside the allowable limit of 170.

Unlike the other sanctioning organizations, the IBF requires fighters participating in title fights to participate in a weight check the morning of the fight at which they cannot be more than 10 pounds heavier than the weight limit of the fight. The other organizations have no weight limit following the official athletic commission weigh-in the day before the bout.

At Friday's official weigh-in, Golovkin was 159.6 pounds and Daniel Jacobs was 159.8 pounds. However, Jacobs (32-1, 29 KOs), owner of the WBA's secondary title and Golovkin's mandatory challenger, is a naturally bigger man and apparently made the decision not to constrain himself following the weigh-in, which will allow him to rehydrate and be stronger on fight night (HBO PPV, 9 ET).

When the fight was made, Jacobs committed to fighting for all of Golovkin's belts. By ditching the IBF challenge, Jacobs will save himself the sanctioning fee that will go with the IBF, which might prove to be a wise decision because Golovkin is a heavy favorite to win.

The Golovkin camp didn't seem to care about Jacobs' decision.

"Gennady is very excited to defend all of his titles against Daniel Jacobs in this matchup of the two best middleweights in the world," said K2 Promotions managing director Tom Loeffler.