Slovakia's Karol Beck denies all accusations against him

Dominik Hrbaty will now partner Michael Mertinak in place of Beck, who also pulled out of Friday's singles.

The 23-year-old's withdrawal also came amid speculation he had failed a drugs test, although he vehemently denied the unconfirmed reports on Thursday.

When asked whether he had produced a positive sample, he replied: "No."

Reports suggested he failed a routine drugs test after Slovakia's Davis Cup semi-final win over Argentina.

He said: "I wasn't surprised because I sort of expected this kind of issue. I have been dealing with this for over two weeks."

Beck not playing in the singles is a huge blow for Slovakia From SK Have your say on Five Live

Slovakia captain Miloslav Mecir acknowledged that Beck's status had disturbed the team.

"Definitely, it brings an element of discomfort to the team, to the spirit of the team," he said.

"But we will try to overcome it."