Hernych now acts as a coach to the Czech tennis player and Wimbledon champion Markéta Vondroušová, alongside Jiří Hřebec.

In 2005, he was the first professional opponent of Andy Murray at the Torneo Godo, a match he won in three sets.

In 2006 he contested his first final on the tour, losing to Mario Ančić in s-Hertogenbosch, Netherlands.

In May 2009 at the BMW Open in Munich, Germany, he joined forces with countryman Ivo Minář to win their first title together in doubles.

In January 2011 at the Australian Open, Hernych posted his best-ever showing in singles play at a Grand Slam event, reaching the 3rd round for the first time.