Photo by Chris Farina/Top Rank

When Filipino-American Nonito Donaire puts his WBA featherweight belt on the line opposite undefeated Jamaican Nicholas Walters on Saturday at the StubHub Center in Carson, Calif., WBO 126-pound counterpart Vasyl Lomachenko will be an interested observer.

Not only are Walters (24-0, 20 knockouts), Donaire (33-2, 21 KOs) and Lomachenko (2-1, 1 KO) among THE RING’s top-rated featherweights at Nos. 3, 4 and 6, respectively, all three are promoted by Top Rank Promotions.

That relationship might mean the winner of Donaire-Walters could yet face Lomachenko, who is slated to make his first defense against Thailand’s Chonlatarn Piriyapinyo (52-1, 33 KOs) in support of Manny Pacquiao’s WBO welterweight title defense against Chris Algieri in Macao, China on Nov. 22.

Would Lomachenko be interested in the Donaire-Walters winner?

“Of course, of course. That’s the whole point is to get as many titles as possible,” said Egis Klimas, Lomachenko’s manager. “There are a lot of possibilities but you don’t know which fight is going to go.”

A former four-division titleholder, Donaire, 31, scored a fifth-round technical decision that dethroned Simpiwe Vetyeka as WBA beltholder in his last fight in May, representing Donaire’s seventh major title.

On the Donaire-Vetyeka undercard, Walters thoroughly dominated two-division titleholder Vic Darchinyan en route to a fifth-round stoppage.

Walters, 28, floored Darchinyan once in the second round and twice in round five on the way to his fourth consecutive stoppage victory.

A two-time Olympic gold medalist from Ukraine, Lomachenko, 26, won the vacant belt by unanimous decision over previously unbeaten Gary Russell Jr. in June.

Before facing Russell, Lomachenko lost a split decision in March to then-WBO titleholder Orlando Salido, who already had lost his belt at the scales after failing to make the 126-pound weight limit. As a result, the title became vacant.

“As you say, we don’t look to much up front. We go fight-by-fight,” said Klimas. “Right now, we’re concentrating on our next fight. But as soon as that fight is going to be done, then we’ll talk to the promoter and see what’s going on next.”

STEVE CUNNINGHAM TO FIGHT WITH BIG HEART VS. NATU VISINIA

Former IBF cruiserweight titleholder Steve Cunningham has continually expressed gratitude for the giving nature of recent rivals who have shown compassion toward the plight of the heavyweight’s ailing nine-year-old daughter, Kennedy Cunningham.

During a 10-round unanimous decision over previously unbeaten Amir Mansour in his last fight in April, Cunningham (27-6, 12 KOs) rose from two fifth-round knockdowns and dropped his opponent in the final round.

But after the fight, Mansour came up with the idea for the Kennedy Cunningham Fundraiser, which has generated support for a child who has spent her life fighting to survive hypoplastic left heart syndrome.

During a Thursday press conference at the 2300 Club in his native Philadelphia, site of Saturday’s clash with Natu Visinia (10-0, 8 KOs), Cunningham thanked Visinia for his contributions to the Kennedy Cunningham Fund.

“I want to thank everyone for their support for Kennedy’s fund. I want to thank Natu’s camp for donating to her fund,” said Cunningham, whose daughter still is awaiting life-saving heart transplant surgery. “This sport is not as savage as people think. We are fathers and husbands.”

Trained by Naazim Richardson, Cunningham will have to subjugate his gratitude toward Visinia in favor of focusing on the task at hand during the bout’s NBC Sports Network broadcast.

“I am the smallest heavyweight in boxing right now. I wish my weight matched my heart. I am Philly to my core. I am born and raised here. This is not new to me. I am here to do a job. Natu and I can go get a beer after the fight,” said Cunningham. “He’s a big power puncher. He’s big. I am a fighter. This is the third undefeated fighter I am fighting as a heavyweight. I am ready to fight. I am a fighter. I have been going through this with Kennedy for nine years.”

A former left guard in football at Southern Illinois University where he majored in criminal justice, Visinia, 30, is coming off a unanimous decision over Jon Bolden in May.

In spite of his kind heart, Visinia said he is “looking to go to war” on Saturday.

“Steve is a world champion. I have nothing negative to say about him. I admire him. He is where I want to be. He’s been eating from a good menu for a long time and I am hungry,” said Visinia. “Some guys need 30 fights before they would face a Steve Cunningham. A fight like this comes along and I jump at it. I have had a pretty rough career. It is a big risk for him to take this fight and I respect him for that. I am going to give Philly what they are coming to see.”

VIKTOR POSTOL TO SPAR WITH MANNY PACQUIAO IN ADVANCE OF CHRIS ALGIERI FIGHT

Junior welterweight Viktor Postol (26-0, 11 KOs) will serve as a sparring partner for Manny Pacquiao in advance of Pacquiao’s Nov. 22 defense of his WBO welterweight title against rising WBO 140-pound beltholder Chris Algieri, who stands 5-foot-11.

“Postol flew out yesterday flew out yesterday to the Philippines and he’ll arrive tomorrow,” said Vadim Kornilov, manager of the 5-11 Postol. “He’ll be one of the sparring partners for Manny Pacquiao and his fight coming up. He’s sparring Manny because he matches the style of Algieri in a way.”

Postol is the WBC’s No. 1-rated contender to face Danny Garcia, who also holds the RING and WBA belts. Postol and Garcia negotiated a step-aside deal which allows each of the boxers to take one fight within the next four months before facing each other.

RUSLAN PROVODNIKOV COULD FACE JOSE LUIS CASTILLO IN MOSCOW

Former WBO junior welterweight titleholder Ruslan Provodnikov (23-3, 16 KOs) could face former lightweight champion Jose Luis Castillo (66-12-1, 57 KOs) on Nov. 28 in Moscow, according to Kornilov.

“The Provodnikov fight is not fully finalized,” said Kornilov, “but it is looking like he might fight Castillo. But the contract is not finalized with Castillo yet.”

In his last bout in June, Provodnikov lost his WBO junior welterweight title by split decision to Algieri. Nicknamed “The Siberian Rocky,” Provodnikov, 30, was coming off a 10th round stoppage of Mike Alvarado, whom he floored twice on the way to winning his belt last October.

Career highlights for Castillo, 40, include twice going the distance in losses to Floyd Mayweather Jr. in April and December 2002, adding the WBC’s 135-pound belt to his RING belt with a split decision over Joel Casamayor in December 2004 and splitting bouts with Diego Corrales in May and October 2005.

But Castillo has faded badly since June 2007, when he was stopped in the fourth round by Ricky Hatton. Although Castillo is 11-4 with 10 knockouts over the course of his past 15 fights, he has been stopped by Alfonso Gomez and lost decisions to Sebastian Lujan, Jorge Paez Jr. and Antwone Smith.