The Turkish Boxing Federation said Tuesday that Guler, along with trainer Seyfullah Dumlupinar, tested positive for the virus.
The Turkish boxing team returned to Turkey after the cancelation of an Olympic qualification event in the U.K.
After first appearing in Wuhan, China in December, the novel coronavirus has spread to at least 175 countries and territories.
The World Health Organization has declared the coronavirus outbreak a global pandemic.
The number of confirmed novel coronavirus infections worldwide has surpassed 521,000, according to data released Thursday by the U.S.-based Johns Hopkins University. That includes more than 23,000 deaths and over 122,000 recoveries.
