United States long jumper Marquise Goodwin has accepted a one-year ban from the US Anti-Doping Agency but is free to play for the San Francisco 49ers in the NFL this season.
Former Olympian Goodwin, 26, says he quit athletics "more than a year ago" to focus on American football and therefore stopped giving Usada his whereabouts for testing.
However, a Usada spokesperson told BBC Sport Goodwin submitted his whereabouts for the first quarter of 2017.
Usada therefore attempted to test him on 17 January, resulting in a missed test - his second whereabouts failure - while the body conducted an out of competition test on Goodwin in his capacity as a track and field athlete on 12 May.
Goodwin's first whereabouts failure occurred when he failed to submit his fourth quarter 2016 filings by the deadline.
His third failure came when he did not supply his second quarter 2017 filings in time.
Under the whereabouts system, athletes must specify where they will be for one hour a day, seven days a week, for three months in advance, as well as where they will be training each day.
A missed test or filing failure constitutes a whereabouts failure and any combination of three breaches in a 12-month period is considered an anti-doping violation.
For Goodwin, who finished 10th in the long jump at London 2012 and has played in the NFL as a wide receiver since 2013, this has resulted in a one-year ban from 1 April 2017, the date of his third whereabouts failure.
'He missed multiple opportunities to inform us'
In a statement, Goodwin said: "I discontinued all practices associated with competing in track and field, including submitting my whereabouts information.
"It appears that because I did not inform Usada of my plans, my name was inadvertently included in their 2017 testing pool."
Usada says Goodwin, who missed out on selection for Rio 2016 at US trials in July last year, has still not informed it in writing as required that he would like to retire from athletics, despite "multiple opportunities over months" to do so.
As an elite track and field athlete he was therefore entered into the world athletics' governing body (IAAF)/Usada registered testing pool.
"He sometimes filed his whereabouts, he was tested and he never informed us - despite being told in writing and through on-line education that he needed to inform us - that he wished to retire or otherwise not participate in the sport," said a Usada spokesperson.
Usada says Goodwin submitted a whereabouts form in the second quarter of 2017 and it conducted an out of competition test in May.
"We always ensure athletes are aware that we are the organisation conducting the tests," said a Usada spokesperson. "We are not involved with the NFL drug testing program."
Usada added they confirmed Goodwin's first whereabouts failure with him and, as with all such cases, notified him in writing that he was still in the registered testing pool.
"What is disappointing is that he was informed he needed to either provide his whereabouts and be available for testing or retire from the sport if he was no longer competing," said Usada.
"He had multiple opportunities over months to do this and was well educated on these procedures but he chose not to do either, and as a result was not able to be tested.
"This is clearly not ideal for us from a testing standpoint."
Why can he still play in the NFL?
Goodwin will not be subject to a ban under NFL rules, the 49ers say.
The NFL is not a signatory of Usada or the World Anti-Doping Code and has its own performance-enhancing substances policy.
Goodwin was drafted by the Buffalo Bills in 2013, playing 49 games in four seasons before signing a two-year deal with the 49ers in March 2017.
In a statement, the 49ers said: "Marquise informed the organisation some time ago that he has no intentions of competing in track and field and has been entirely focused on his football career for more than a year."
"We have been in touch with the League office regarding this matter, and understand that Marquise will not be subject to discipline under the NFL policy on performance-enhancing substances as a result of Usada's decision."
Goodwin, who won the Diamond League event in Birmingham in June 2016, added he has never failed a test and has always been "compliant with each and every protocol and policy" during his competitive athletics career.