Andy Murray is confident that he can win the Davis Cup tie for Great Britain when he faces American John Isner today, according to his brother Jamie.

Great Britain need one win in the last two singles rubbers, with James Ward playing against Donald Young if Murray fails to triumph.

"I don't think Isner's going to be back-flipping out of bed to play Andy," Jamie Murray told BBC Sport.

"I'd rather be in Andy's shoes than Isner's. I'm sure Andy will be pretty confident.

"I guess with his [Isner's] serve you've always got a chance but I'd never back against Andy in this kind of situation."

Jamie featured in yesterday's fifth-set doubles defeat to Bob and Mike Bryan.