Jan Mertl
Jan Mertl (born 3 January 1982) is a Czech former tennis player who competed mainly on the ITF Futures Tour and ATP Challenger Tour. On 23 July 2007, he reached his highest ATP singles ranking of 163.Mertl made his ATP main draw debut at 2016 Swiss Open Gstaad, defeating Yann Marti to score his first ATP-level win.
Mertl is the coach of Czech WTA player Markéta Vondroušová. Provided by Wikipedia