Two heavyweight champions are looking to slug it out in a grudge match this Saturday night in Hamburg, Germany.

David Haye will put his WBA title on the line against Wladimir Klitschko's WBO, IBF, and IBO crowns, in a heavily anticipated fight in a weight class that has struggled to draw major interest.

With Klitschko's (55-3, 49 KO), and Haye's (25-1, 23 KO) injuries over the past couple years, it was uncertain that this mega-fight was ever going to happen. According to Klitschko, the contract states that Haye must enter the ring first to assure his presence come fight night.

Trash talking was definitely present during a recent press conference.

Arriving late to the press conference, London-born David Haye did not treat Dr. Klitschko, as he likes to be referred to, with any respect. Klitschko called Haye a princess, which infuriated Haye, who later refused to partake in a hand shake. I will inflict the most brutal execution ever seen in the ring, Haye told the media. This isn't a tickling contest or a pillow fight, it is war and his head is coming off.

Haye extended his insults to Klitschko's brother, Vitali, calling them both frauds who have only fought little fat puddings who turn up for a pay check. Haye has also previously sported a t-shirt with the brothers decapitated.

Haye is riding a 15-fight win streak dating back to 2004, but made the switch from cruiserweight to heavyweight in 2008. Haye succeeded the WBA Heavyweight belt from the seven-foot Nikolay Valuev (50-2, 34KO) in 2009.

Klitschko is not far behind with 13 consecutive wins since 2004, and having collected his three major belts since 2006.

Both boxers are certainly in top shape. Haye is more youthful at age 30, while the 35-year-old Klitschko is far more experienced as a heavyweight.

KEYS TO THE FIGHT:

Haye must be careful against Klitschko's powerful jabs. The Ukrainian heavyweight, trained by Emanuel Steward, dictates fights at his own pace and uses his whole body to throw straight rights. Haye's offense must be sharp from the beginning round otherwise he could lose a chance to breakdown Klitschko.

If the fight is kept at the center ring, Haye can use his fast hands, and take a page out of Klitschko's book by working off his back foot. However, Klitschko is a defensive fighter and uses his left hand to guard even when he attacks.

Because of Klitschko's three-inch height and three-inch reach advantage, Haye must avoid clinching and holding, and find a balance quickly, to throw punches in volumes.

Regarding the detestable t-shirt of Haye holding the severed heads of the Klitschko brothers, Haye responds that, in no way shape or form do I regret doing any of the controversial stuff that I've done or said.

Unlike Haye, Klitschko doesn't bark. He is a powerful threat but he is a natural cruiserweight and this will be the first time he has faced a real heavyweight, says the modest Klitschko. And he considers the fight as, the most serious challenge of my career.

It certainly is a challenge, as winning the WBA Heavyweight title means that Klitschko will unify all the belts in his division. And with a taste of success, Haye is coming to the fight hungry.