Jamie Murray says he is disappointed by brother Andy's decision not to join his Great Britain team-mates in their Davis Cup clash against Argentina.

The World Group meeting, which starts today at Parque Roca, is a tough encounter for John Lloyd's recently-promoted team and Murray's withdrawal with a knee complaint has stacked the odds even further against them.

Andy Murray said he was advised not to play on clay in Argentina after playing on hard courts in Australia and before playing on indoor surfaces. But Jamie believes his brother is being overly cautious in deciding to sit out Great Britain's crucial World Group meeting in Buenos Aires.

"It kind of affects the way we feel about him," Jamie Murray said. "I think it's disappointing that he chose not to come. From what I have been reading he hasn't come out and said he's injured, it's more a prevention thing. I think if he had really wanted to push himself he could have come here."

Andy Murray is preparing to compete in an ATP event in Marseilles instead and it is not a decision which his brother can sympathise with.

"He obviously felt it was more important for him to concentrate on going to Marseilles and doing well rather than coming here. It was a shock to me and for the team it's very disappointing. I wasn't aware he had a problem. I last spoke to him in Australia just before he left [the Australian Open].

"There's not much to say. I'm here working hard for the team and trying to do my best and he is at home doing whatever he is doing."

He added: "He had the ability to win two singles matches here. He is in the top ten in the world and it's not by fluke."

Argentina have lost Juan Monaco to an ankle injury but can boast the talented Sebastian Prieto as his replacement in a team that also includes top-60 stars David Nalbandian (ninth), Agustin Calleri (41st) and Jose Acasuso (50th).

In the absence of 20-year-old Murray, Alex Bogdanovic is Lloyd's highest-ranked competitor with a placing of 188.