Andy Murray has withdrawn from Great Britain's Davis Cup tie against Ukraine because of a virus that has laid him lower than any previous illness and is threatening to seriously affect his season.

The world No4 has been ordered to rest for another week as a result of the virus which forced him to pull out of the Dubai tournament last Thursday and also affected his Australian Open challenge.

Tests at the National Tennis Centre in Roehampton at the weekend confirmed he still has a problem, forcing him to miss the Davis Cup match, which starts in Glasgow on Friday.

“I'm very disappointed that I won't be playing but the doctor has told me I need complete rest for at least seven days, and I have to respect that,” said Murray. “This virus has hit me harder than any illness I've had before and I still feel terrible.”

Without Murray, the hosts have a much tougher task to beat Ukraine, whose top player is the world No125 Sergiy Stakhovsky. By contrast Britain's leading man this week is Joshua Goodall, who is ranked 192nd. Team captain John Lloyd had expected to lose Murray and will now look to Goodall and Chris Eaton in the singles, with Colin Fleming likely to join Ross Hutchins in the doubles.

Lloyd said: “It's obviously disappointing that Andy can't play but with the support of a vocal home crowd I firmly believe this is a very winnable match for us.”

The winners of the Europe/Africa Zone Group I tie will feature in a September play-off for a place in the World Group.