It's not the first time Overeem has run afoul of the NSAC. He was granted a conditional license to fight Brock Lesnar at UFC 141 after missing a pre-fight drug test ordered by the commission, which reinstated out-of-competition testing this past July.
Answering to the commission via telephone during an NSAC hearing held three weeks prior to UFC 141, Overeem said he missed the test because he had flown back to his native Holland to care for his ailing mother and wasn't made aware of the obligation. When he got word, he submitted an invalid blood test conducted by his personal doctor and then submitted urine that wasn't tested.
The NSAC gave him a license on the condition that he submit to a drug test conducted by an accredited laboratory, which he did two days later (and subsequently passed), as well as pass a drug test upon arriving in the U.S. for the Lesnar fight and submit to two random tests.
This past Tuesday's test served as one of those random tests, which also followed a fight-night test at UFC 141.