Sample collectors from the Voluntary Anti-Doping Association have visited Oscar Valdez 11 times since he left the ring the night of September 10 at Casino del Sol in Tucson, Arizona.

They first visited the unbeaten WBC super featherweight champion in his locker room following his 12-round, unanimous-decision defeat of previously unbeaten Brazilian contender Robson Conceicao. Then VADA arrived when he was sleeping on a Sunday morning. Again when he was having dinner with his family. Another time when he was playing with his kids.

Valdez admits those random visits to his home for blood, urine and sometimes samples of both became “annoying.” It is a small price to pay, according to the Nogales, Mexico, native to provide evidence through the remainder of his career that he is a clean fighter.

VADA has tested Valdez more than usual between bouts in accordance with an agreement he made with the WBC following the  performance-enhancing drug ordeal that marred his narrow victory over Conceicao.

“I agreed because when you’ve got nothing to hide, I shouldn’t be worried, right?,” Valdez told BoxingScene.com. “I always put in my contracts I want the VADA testing because I’m trying to protect myself from the other fighter. It didn’t make sense that I would put in my contracts that I want the VADA tests just for me to start taking stuff. It wouldn’t make sense for me to try to take anything, as far as a performance-enhancing drug, if I’m the one putting in the contracts that I want VADA testing.”

The 31-year-old Valdez realizes, of course, that he has plenty of skeptics in advance of his showdown with Shakur Stevenson on April 30 in Las Vegas because Valdez tested positive for Phentermine prior to his title defense against Conceicao. Phentermine, a stimulant banned by VADA both in and out of competition, was detected in Valdez’s “A” and “B” samples submitted August 13, four weeks before he encountered Conceicao.

Valdez maintains his innocence, but he admitted during an interview with BoxingScene.com on Wednesday that this Phentermine problem impacted his preparation and performance against Conceicao.

“I’m just gonna be as real as possible,” Valdez said. “I was affected [by] the comments of people calling me a cheater, who said that I’m using something that’s prohibited. That’s not the case. I’ve always worked hard. I’ve always been a clean fighter. And the fact that they were pointing me out, without saying the facts, without saying what this substance was, that it was a clear mistake. And it never should’ve came up positive because different rules for organizations call it different.

“And the fact that I was called a cheater broke my heart, broke me down. I was a kid once who looked up to all these great fighters. And when I would hear stories about fighters using banned substances, PEDs, it would change my mind completely about fighters. So, the fact that was happening to me, that they were saying I was cheating in the sport of boxing, which I would never do, it brought me down. I really lost focus because I worked so hard my whole career, and to be criticized for that one thing, which shouldn’t be considered a banned substance, it just brought me down.”

Valdez became collateral damage to some degree because disparate requirements from VADA and the World Anti-Doping Agency helped him go through with the Conceicao bout, despite that he violated VADA protocol.

The Pascua Yaqui Tribe Athletic Commission, which regulated the Valdez-Conceicao card, approved Valdez’s license application because all state and tribal commissions in the United States that are affiliated with the Association of Boxing Commissions adhere to WADA’s standards. WADA permits Phentermine “out of competition,” as long as it isn’t detected after 11:59 p.m. local time the day before an event.

“If people were to look at the details or educate themselves to what this really was, they would realize, ‘Oh, it’s not a banned substance,’ ” Valdez said. “It’s not something that’s actually helping me in any way. It’s not a performance-enhancing drug is what I’m trying to say. It’s more of a diuretic. The only difference was this banned substance was if this banned substance would’ve come up 24 hours before the weigh-in, it would’ve been positive for the WADA. But through the VADA, if you’re on vacation or training camp, it doesn’t matter when, it’s prohibited. So, the only thing it would help with was losing weight, which didn’t make sense for me using that because it was three weeks away from the weigh-in.

“So, it was clearly a misunderstanding or clearly a mistake that doesn’t help me in any way to becoming a stronger fighter or hitting harder or just making me a better fighter at all. So, the fact that people don’t educate themselves, to see what the substance really was, it’s really a bummer and it really sucked because, like I said before, I’ve always been a clean fighter and I’ve always hated fighters who actually try to cheat. I’m old school. I’m old-fashioned. Just work hard, do what you’ve gotta do in the gym and you win the fights. And that’s the way I still am to this day, so if that stays for the rest of my life, well, that sucks because I’ve always been a clean fighter.”

Stevenson is among those that doesn’t believe Valdez’s version of what transpired during his training camp while he prepared to face Conceicao. That is why the unbeaten WBO junior lightweight champion’s team pushed for the most advanced VADA testing possible prior to their 12-round, 130-pound title unification fight, which ESPN will televise next month from MGM Grand Garden Arena.

“He got caught cheating, so he’s just gotta deal with everything that come with it,” Stevenson said. “VADA’s about to make sure that they test him a lot more. We’re just trying to make sure he don’t cheat or nothing like that.”

Stevenson (17-0, 9 KOs) recalled VADA tested him three times while he was training for his fight against Jamel Herring (23-3, 11 KOs), whom Stevenson stopped in the 10th round October 23 at State Farm Arena in Atlanta to become a two-weight world champion. The 2016 Olympic silver medalist from Newark, New Jersey, expects VADA to test him more than that while he trains in Las Vegas for his fight versus Valdez (30-0, 23 KOs), who is training in San Diego.

“As a fighter, you’ve gotta understand we’re going in there and putting our life on the line,” Stevenson said. “You know, people have died in the ring, all types of stuff. At the end of the day, we’re just making sure everything check out, make sure everything is good. I don’t wanna be in there fighting with no cheater.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.