TAMPA, Fla. --

One day after Lyoto Machida's upcoming middleweight fight with Dan Henderson was canceled following Machida's admission that he used a banned substance, one of UFC's top light heavyweights said the USADA needs to be "more specific" about which over-the-counter products violate the UFC's Anti-Doping Policy.

Glover Teixeira addressed Machida's positive test Thursday at open workouts ahead of his fight with No. 7 light heavyweight Rashad Evans at UFC on FOX Fight Night in Tampa this Saturday. Teixeira-Evans previously shared top billing with Machida-Henderson prior to Machida's disclosure and the subsequent cancellation of his bout.

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"Listen, I think it's great," Teixeira said of the USADA testing program, which has been in place since July 2015. "I love it. I think it helps the fighters a lot, you know? I think it's a great thing. I believe this is a different level. I wish they'd be more specific, though."

In a Facebook post Wednesday, Machida said he took a product called 7-Keto, which contains the drug DHEA. In the post, the 37-year-old said the substance is "found in products sold at every supplement store and it's very popular." Machida said he was unaware the product was in violation of UFC policy, a common problem among fighters that Teixeira said needs to be addressed.

"Lyoto got caught with something that, I don't know, something that he bought over the counter," Teixeira said. "You never know.

"Can we take NyQuil?" the Brazilian continued. "Can we take Advil? I don't know right now. I really don't know, if I have a headache, if I can go and take an Advil. Really, I don't know. They put a scientific name that we don't know. When we buy over the counter stuff and we don't know, this is the hardest part for me."

Even so, Teixeira said he believes the testing is working -- even if what is and isn't illegal isn't always clear.

"I have no issue with it," Teixeira stressed. "I just am worried a little bit about everything. To tell you the truth, I'm a coffee person. What about coffee right now, in Florida? They say something about caffeine and they keep telling me about all these things about caffeine. I'm like, 'Hey, can I drink coffee?' Not too much. But what's too much?

"What's too much for you?" Teixeira added. "For me, 12 shots is a good day."

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