UFC 183
| Industry | Mixed martial arts event |
|---|---|
| Founded | January 31, 2015 |
| Headquarters | Las Vegas , United States |
UFC 183: Silva vs. Diaz took place on January 31, 2015, at the MGM Grand Garden Arena located in Las Vegas, Nevada.
Background
The main event featured a middleweight clash between former UFC Middleweight titleholder Anderson Silva and ex-champion of both WEC and Strikeforce Welterweight divisions, Nick Diaz.
Initially planned for UFC Fight Night: Shogun vs. St. Preux, a flyweight contest between Ian McCall and John Lineker was postponed due to McCall suffering a blood infection, leading to its rescheduling at this event.
Similarly, a middleweight matchup featuring Ed Herman versus Derek Brunson was moved here after Brunson withdrew from their original booking at UFC on Fox: dos Santos vs. Miocic because of illness.
During the weigh-ins, both Kelvin Gastelum and John Lineker failed to make weight on their initial attempts, registering 180 lb and 130 lb respectively. As a result, each was penalized by forfeiting 30% of their fight purses to their opponents, Tyron Woodley and Ian McCall. This incident marked Lineker’s fourth time missing weight in the UFC. Consequently, UFC President Dana White ordered both athletes to compete in higher weight classes moving forward due to persistent issues with weight cutting.
A featherweight fight between Jimy Hettes and Diego Brandão, scheduled for the Fight Pass preliminary card, was canceled shortly before the event after Hettes lost consciousness backstage and was hospitalized as a precautionary measure. Despite the cancellation, both participants were compensated with their show money.
Failed drug tests
On February 3, announcements revealed that both headliners failed drug screenings. Anderson Silva tested positive in a pre-fight sample collected by the Nevada State Athletic Commission on January 9, detecting drostanolone metabolites—an anabolic steroid—and androsterone, a banned form of endogenous testosterone. Silva underwent additional testing on January 19 and on fight night, with further analysis pending to confirm these findings. Post-fight testing indicated that Nick Diaz had marijuana metabolites exceeding permissible limits, marking his third violation related to marijuana use. NSAC chairman Francisco Aguilar confirmed that the fight's official outcome remained unchanged pending a commission vote regarding any sanctions or potential result modifications.
On February 9, Silva’s test from January 19 showed no prohibited substances. However, on February 11, reports surfaced that he failed another UFC 183-related drug test involving an unidentified substance. During the NSAC meeting on February 17, it was disclosed that Silva’s second failure pertained to fight night samples: a positive pre-fight test for drostanolone metabolites along with post-fight positives for oxazepam and temazepam—both prescribed for anxiety and insomnia treatment.
The disciplinary hearing held on August 13 examined Silva’s defense claiming contamination from a sexual enhancement supplement as the source of the drostanolone positives and cited procedural irregularities given two cleared tests from January 19 and post-fight samples. Silva acknowledged using benzodiazepines for stress relief and sleep but could not clarify the presence of androsterone. The commission dismissed his defense, imposing a one-year suspension retroactive to the fight date, levying a $380,000 fine (comprising his entire win bonus plus 30% of his show purse), and overturning his win to a no contest.
Diaz’s hearing was postponed until September; on September 14 he received a five-year suspension alongside a $165,000 fine (33% of his show purse). After appealing in January 2016, Diaz’s penalty was reduced to an eighteen-month suspension with a $100,000 fine.
Bonus Awards
A $50,000 bonus was granted to the following fighters:
- Fight of the Night: Thales Leites vs. Tim Boetsch
- Performance of the Night: Thales Leites and Thiago Alves
Reported Payout
The disclosed fighter earnings reported by the Nevada State Athletic Commission do not include sponsorship deals or UFC "fight night" bonuses:
- Anderson Silva: $800,000 (which includes a $200,000 victory bonus) vs. Nick Diaz: $500,000
- Tyron Woodley: $139,000 (with a $65,000 win bonus included) defeated Kelvin Gastelum: $21,000 ^
- Al Iaquinta: $36,000 (including an $18,000 win bonus) defeated Joe Lauzon: $36,000
- Thales Leites: $48,000 (incorporating a $24,000 win bonus) defeated Tim Boetsch: $52,000
- Thiago Alves: $84,000 (with a $42,000 win bonus) defeated Jordan Mein: $22,000
- Miesha Tate: $76,000 (including a $38,000 win bonus) defeated Sara McMann: $25,000
- Derek Brunson: $50,000 (which includes a $25,000 win bonus) defeated Ed Herman: $47,000
- John Lineker: $35,700 (including a $21,000 win bonus) defeated Ian McCall: $22,300 ^^
- Rafael Natal: $58,000 (with a $29,000 win bonus) defeated Tom Watson: $16,000
- Ildemar Alcântara: $32,000 (including a $16,000 win bonus) defeated Richardson Moreira: $8,000
- Thiago Santos: $26,000 (with a $13,000 win bonus) defeated Andy Enz: $8,000
^ Kelvin Gastelum was penalized 30% of his purse ($9,000) for missing weight; this amount was awarded to Woodley who stated he would return it.
^^ John Lineker was fined 30% of his earnings ($6,300) due to failing to make weight; the sum was given to McCall.