Sam Querrey has withdrawn from the St Petersburg Open after the ATP confirmed a player tested positive for COVID-19.

The ATP released a statement on Monday saying an unnamed player is now isolating after testing positive for the virus and a contact-tracing process is underway to notify people who may have come into contact with him.

While they did not confirm Querrey was the player in question, the American no longer features on the draw and his first-round opponent, Denis Shapovalov, is now scheduled to play lucky loser Viktor Troicki.

On court, meanwhile, Stan Wawrinka saved three match points to overcome Dan Evans 3-6 7-6 (7-3) 7-5, wildcard Aslan Karatsev saw off Tennys Sandgren 7-5 3-6 7-5 and Cameron Norrie edged past eighth seed Taylor Fritz 6-4 4-6 6-3.

In Cologne, Oscar Otte beat Jan-Lennard Struff in an all-German clash, while Steve Johnson saw off Filip Krajinovic – the fifth seed – in a deciding set.

At the Forte Village Sardegna Open in Italy, teenager Lorenzo Musetti boosted his burgeoning reputation by beating Pablo Cuevas in straight sets, while Jiri Vesely overcame Kamil Majchrzak.