Mike Alvarado has spilled his blood in previous slugfests. He doesn’t want to spill too much of it if he doesn’t have to during his anticipated showdown with Brandon Rios on HBO on Saturday. 

The junior featherweight championship bout between Nonito Donaire and Toshiaki Nishioka is the main event of an HBO-televised show from the Home Depot Center in Carson, Calif., on Saturday, but the main attraction of the Top Rank promotion is the anticipated Brandon Rios-Mike Alvarado fight.

The junior welterweight showdown between the punishing former lightweight beltholder and the bruising undefeated 140-pound contender is the reason this show has sold close to 4,000 more tickets than Donaire’s last appearance – a unanimous decision over Jeffrey Mathebula in July – at the 8,000-seat outdoor arena.

Fans know what to expect from the two unbeaten bangers, who have a combined 63 victories, 45 by knockout: one a hell of a fight. Neither fighter has engaged in a “snoozer;” both have been in their share of slugfests, both have spilled their share of blood making fans happy.

So those who follow boxing are expecting Rios-Alvarado to be an elite battle of attrition that could approach the level of violence that the first Diego Corrales-Jose Luis Castillo fight produced.

Even technical boxers are looking forward to watching the two card-carrying tough guys go at it.

“I for one am excited for the @Brandon_Rios1 and @MileHighMike303 fight. #FOTY candidate. Remember I was a #fanfirst,” undefeated junior middleweight titleholder Austin Trout recently tweeted on his @NoDoubtTrout Twitter page.

Rios, a 26-year-old Kansas native who lives and fights out of Oxnard, Calif., is just as excited as everyone else.

“I’m still waiting for my Gatti-Ward fight,” Rios said, referencing the classic series of brutal ring battles between the late Arturo Gatti and Micky Ward, during a recent media conference call. “Hopefully, this is that fight.”

Alvarado, THE RING’s No. 5-rated junior welterweight, is also excited.

“Everyone loves a blood-and-guts war, everyone wants to see that kind of fight,” he told RingTV.com after a sparring session at The Rock gym in Carson, Calif., last Thursday.

However, don’t expect to see Alvarado charge out of his corner and invite punishment from Rios just to appease the fans and his own admitted zest for a good scrap. If the 32-year-old veteran from Denver, Colo., can get away with only spilling a pint of blood instead of a quart, he says he’s going to do that.

“I love bloody toe-to-toe brawls, I love ring wars like Gatti-Ward and Corrales-Castillo,” Alvarado said, “but at the same time, I’ve got to I’ve got to ask myself ‘Dude, do I really want to be that guy who takes all those punches?’

“I can stand and slug with Brandon Rios all night long and be the bigger, stronger man. The fight will play out however it does – most likely the war that everybody wants to see – but I can also control the fight with my skills.

“I have underrated boxing ability that I don’t always show because sometimes I just like to fight it out, but I like to think I’m past that (mentality). I’m going to make (the fight) as easy as I can for myself.”

That’s not what hardcore fans want to hear from Alvarado. They want to hear from the warrior with the take-no-prisoners attitude, the man who was busted up and trailing on the scorecards against Breidis Prescott last November but simply refused to lose.

Alvarado smiles when people bring up his come-from-behind 10^th-round stoppage of the rangy Colombian on the undercard of the Manny Pacquiao-Juan Manuel Marquez III pay-per-view show.

“I’m proud of that fight,” he said. “It was the fight of the night and it was great to win like that on a big pay-per-view show but I showed more than just guts in that fight. I had to make some technical adjustments to be able to get to Prescott.”

There he goes again, using words like “technical” to describe what he does in the ring. What gives?

Alvarado says boxing fans wouldn’t be so surprised to hear him talk about skills, technique and adjustments if they were more familiar with his wrestling background.

Colorado legend has it the two-time high school state wrestling champ was unbeaten in anywhere from 80 to 100 matches. Alvarado says he didn’t simply overpower his wrestling opponents; he beat them with technique and intelligence.

“I was swift and smooth,” he said with a proud smile, “I was the Floyd Mayweather of wrestling.”

Alvarado only boxed in the amateur ranks for four years, compiling around 40 bouts, winning most of them and only losing to the top U.S. amateur boxers at the time – including Lamont Peterson and Andre Dirrell, with whom he split two fights.

“I was raw when I turned pro but I wanted to master boxing as I did with wrestling,” Alvarado said. “I love to learn the craft of boxing – every technique there is to learn, the whole science of it.”

He admits that it has been a slow evolution.

Alvarado grew from the one-dimensional stalker who was rocked by young journeyman Hilario Lopez in his eighth pro bout (on undercard of the first Pacquiao-Erik Morales fight in 2005) to the more polished prospect who struggled to narrowly outpoint current 154-pound contender Carlos Molina two years later to the technically sound boxer-puncher who scored easier than expected victories against veteran Michael Clark (TKO 1), streaking Jesus Rodriguez (UD 10), once-beaten puncher Michel Rosado (TKO 7) and former titleholder Cesar Bazan in consecutive bouts in 2007 and ’08.

Alvarado likely would have been ready for the HBO spotlight or even a title shot in 2009 or 2010 if he hadn’t served two jail stints for driving-related offenses and for breaking probation during that time.

Alvarado got his life and career back on track last year, fighting four times in 2011 and by kicking off this year with a unanimous decision over tough fringe contender Mauricio Herrera in April.

“I’ve had a few bumps in the road but that helped me realize how important my career is,” he said.

Not just to him, but to his three daughters – 10-year-old Miliani, 5-year-old Ariyah and 3-year-old Arianna – who he takes care of when he’s not in camp.

“They motivate me,” he said. “They depend on me and that brings my heart out in this sport.”

That heart will be on display Saturday night, but so will Alvarado’s mind. He wants to limit his punishment in order to have something left for future opportunities.

“I’ve been waiting for an HBO appearance for years,” Alvarado said. “This fight catapults me to the next level in the junior welterweight and welterweight divisions.

“I’m the No. 1 contender in the WBO. Juan Manuel Marquez is the WBO champion. A fight with him is a dream fight. And if I can fight him then maybe fights with Manny Pacquiao and Floyd Mayweather are possible. Those are great fighters.”

First, he must win a potentially great fight.

Photos / Jewel Samad-AFP and Harry How-Getty Images