![Leonardo Mayer, of Argentina, serves to Roger Federer, of Switzerland, at the Western & Southern Open tennis tournament, Friday, Aug. 17, 2018, in Mason, Ohio. (AP Photo/John Minchillo Stock Photo - Alamy Leonardo Mayer, of Argentina, serves to Roger Federer, of Switzerland, at the Western & Southern Open tennis tournament, Friday, Aug. 17, 2018, in Mason, Ohio. (AP Photo/John Minchillo Stock Photo - Alamy](https://c8.alamy.com/comp/2MMRAHE/leonardo-mayer-of-argentina-serves-to-roger-federer-of-switzerland-at-the-western-southern-open-tennis-tournament-friday-aug-17-2018-in-mason-ohio-ap-photojohn-minchillo-2MMRAHE.jpg)
Leonardo Mayer, of Argentina, serves to Roger Federer, of Switzerland, at the Western & Southern Open tennis tournament, Friday, Aug. 17, 2018, in Mason, Ohio. (AP Photo/John Minchillo Stock Photo - Alamy
![Leonardo Mayer of Argentina returns the ball to Jan-Lennard Struff of Germany during the men's singles first round match at the Wimbledon Tennis Championships in London, Monday July 2, 2018. (AP Photo/Kirsty Leonardo Mayer of Argentina returns the ball to Jan-Lennard Struff of Germany during the men's singles first round match at the Wimbledon Tennis Championships in London, Monday July 2, 2018. (AP Photo/Kirsty](https://c8.alamy.com/comp/2MN2ND6/leonardo-mayer-of-argentina-returns-the-ball-to-jan-lennard-struff-of-germany-during-the-mens-singles-first-round-match-at-the-wimbledon-tennis-championships-in-london-monday-july-2-2018-ap-photokirsty-wigglesworth-2MN2ND6.jpg)
Leonardo Mayer of Argentina returns the ball to Jan-Lennard Struff of Germany during the men's singles first round match at the Wimbledon Tennis Championships in London, Monday July 2, 2018. (AP Photo/Kirsty
![Argentina's Leonardo Mayer plays against the Czech Republic's Stepanek on the 6th day of the Tennis World Team Cup at Rochusclub in Duesseldorf, Germany, 25 May 2012. Photo: CAROLINE SEIDEL Stock Photo - Alamy Argentina's Leonardo Mayer plays against the Czech Republic's Stepanek on the 6th day of the Tennis World Team Cup at Rochusclub in Duesseldorf, Germany, 25 May 2012. Photo: CAROLINE SEIDEL Stock Photo - Alamy](https://c8.alamy.com/comp/D64DNP/argentinas-leonardo-mayer-plays-against-the-czechrepublics-stepanek-D64DNP.jpg)