RING middleweight champion Sergio Martinez is being guarded daily by armed security personel in the wake of threats against him and an incident of weekend vandalisim.

The developments led to the cancelation of this past Tuesday’s scheduled open workout for the media at Martinez’s Oxnard-based training camp.

“We have 24/7 armed security around. They will be with us all the way up to the fight,” said manager, Sampson Lewkowicz of Martinez (49-2-2, 28 knockouts), who is preparing to meet WBC belt-holder Julio Cesar Chavez Jr. (46-0-1, 32 KOs) on Sept. 15 at The Thomas and Mack Center in Las Vegas.

“Nothing else has changed in the training camp. We’re still training in Ventura, Calif., but we just have very professional security people around us.”

Lewkowicz and Martinez’s promoter, said Lou DiBella, said they believe that the incident is isolated, although they deemed it necessary to take precautions. A police report has been filed, according to DiBella.

“There was paint on one of the cars, and on part of the house. We strongly believe that whoever did that is a human being with no tomorrow,” said Lewkowicz, referring to the vandalism.

“I don’t think that any particular group would do this, but only a low-life who has nothing else to do but to take the risk of this magnitude. I strongly believe that a human being like Martinez has no true enemies.”

24/7: CHAVEZ JR.-MARTINEZ DEBUTS ON SATURDAY

The debut of HBO’s 24/7: Chavez Jr.-Martinez will air on Saturday at 11:45 p.m. as the first episode chronicling the events leading up to the showdown between the two fighters.

WILLIE NELSON-JOHN JACKSON SLATED FOR CHAVEZ JR.-MARTINEZ

Junior middleweight Willie “The Great” Nelson (18-1-1, 11 KOs) will be after his third straight win against hard-hitting John “Dah Rock” Jackson (13-0, 12 KOs) on Chavez Jr.-Martinez undercard.

Standing 6-foot-4, with a 77-inch reach, Nelson, 25, is co-promoted by Rumble Time Promotions and DiBella Entertainment and coming off a victory in May over previously unbeaten Yudel Jhonson, whom he fought as a late replacement on just 11 days notice.

“We saw an opportunity to beat a fighter everybody thought so highly of. I took the fight knowing a win would get me back on the scene,” said Nelson, who is trained by Jack Loew and is the son of three-time, two-division champion Julian Jackson

“Jackson had a decent amateur background in the Virgin Islands. He supposedly can punch. I want him on the outside because I’ve been learning how to use distance with my height and reach advantages. Before, I just went in fighting, not taking advantage of being the bigger, taller fighter.”

MARCO HUCK DEFENDS AGAINST FIRAT ARSLAN ON NOV. 3

RING No. 1-rated cruiserweight Marco Huck (34-2-1, 25 KOs) will defend his belt against Firat Arslan (32-5-2, 21 KOs) in a clash of German-based fighters on Nov. 3 from the Gerry Weber Stadium in Halle, Nordrhein-Westfalen, Germany.

After losing February’s disputed majority decision to WBA regular heavyweight beltholder Alexander Povetkin, Huck dropped back into the cruiserweight ranks, where he battled to a draw with Ola Afolabi in May in defense of his WBO title.

Huck had won 15 straight fights as a 200-pounder, including 11 by knockout, since falling by 12th-round stoppage to Steve Cunningham in December of 2007.

Huck had defended his crown against Afolabi by unanimous decision in December of 2009.

Arslan has won three of his past four fights by stoppage, but is coming off a draw with Alexander Alekseev in May.

“He is a real machine, constantly putting pressure on his opponents. Moreover, he is a southpaw,” said Huck. “I will have to be in top condition.”

Huck is promoted by Sauerland event, which recently signed former light heavyweight titleholder Jurgen Brahmer.

UNBEATEN JORGE MAYSONET FIGHTS ON GENNADY GOLOVKIN-GRZEGORZ PROKSA CARD

Power punching junior welterweight Jorge “Machito” Maysonet, Jr. (8-0, 7 KOs), of Catano, Puerto Rico will face journeyman Bryan Abraham (6-13-2, 6 KOs), of Schenectady, N.Y., on the undercard of the HBO-televised main event between WBA middleweight belt-holder Gennady Golovkin and Grzegorz Proksa at The Turning Stone Resort and Casino in Verona, N.Y.

“I know my opponent is ambidextrous, and he’s also a heavy puncher, but the crowd can expect a lot of action on my part because I don’t like running,” said Maysonet. “I like fighting head on but I’m ready to obtain the victory by any means necessary.”

Trained by his father and former title-holder, Jorge Maysonet Sr., Maysonet, 22, is promoted by Gary Shaw Productions, Warriors Boxing and Universal Promotions.

DEMETRIUS ANDRADE RETURNS ON SEPT. 20

Southpaw middleweight Demetrius “Boo Boo” Andrade (17-0, 12 KOs) will be after his fourth straight knockout when he headlines the 11th-annual Fight To Educate against an opponent to be determined on Sept. 20 at Verizon Wireless Arena in Manchester, N.H.

The 2008 U.S. Olympian and former 2007 world amateur champion will be participating in a venture geared toward helping children and seniors in need.

WBC INITIATES PENSION FUND FOR EX-BOXERS

The signatures of 12 former champions will be engraved on watches designed by the Swiss company Hublot, each of which is to be sold at an auction whose proceeds will benefit retired fighters who have fallen on hard times.

The participating former champions are Ray Leonard, Thomas Hearns, Mike Tyson, Julio Cesar Chavez, Ken Norton, George Foreman, Larry Holmes, Lennox Lewis, Roberto Duran, Oscar De La Hoya, Jeff Fenech and Azumah Nelson.

Company chairman Jean-Claude Biver will then work with the WBC to develop a pension fund, according to a release by the WBC.

EDWIN RODRIGUEZ, ZSOLT ERDEI, VIC DARCHINYAN HIGHLIGHT HBO TRIPLE-HEADER

An HBO Boxing After Dark triple-header to be promoted by Lou DiBella Entertainment on Sept. 29 will feature bouts bewteen middleweights Edwin “La Bomba” Rodriguez (21-0, 14 KOs) and Jason Escalera (13-0-1, 12 KOs), junior featherweight Luis Del Valle (16-0, 11 KOs) and former title-holder Vic Darchinyan (37-5-1, 27 KOs) and former belt-holder Zsolt Erdei (33-0, 18 KOs) in a light heavyweight bout opposite Isaac Chilemba (19-1-1, 9 KOs).

Billed as “Road To Glory,” the event will be televised from the MGM Grand at Foxwoods, in Mashantucket, Conn., and is being promoted by DiBella, Joe DeGuardia’s Star Boxing and Gary Shaw Productions.

Photo by Naoki Fukuda

Photos by Chris Farina, Top Rank

Photo by Wende

Photo by Doug Fischer

Photo by Chris Cozzone, Fightwireimages.com

Lem Satterfield can be reached at [email protected]