US Davis Cup captain Patrick McEnroe announced on Tuesday that Querrey will replace James Blake in the semi-final tie September 19-21.

'He said he needed a break, and we respect that,' McEnroe said of Blake.

'This also is a great opportunity for Sam, who had a solid year, strong results on clay and has been a loyal practice partner for this team.'

The 20-year-old's performance at the US Open continued a breakthrough season in just his second year as a pro.

He won his first career ATP Tour title in March and defeated former French Open champion Carlos Moya on clay en route to the quarter-finals of the Monte Carlo Masters Series.

Andy Roddick and the doubles tandem of Mike and Bob Bryan had already been named to the US team.

World No. 1 Rafael Nadal, who was upset by Andy Murray in the semi-finals of the US Open, will be part of the Spanish squad.

The United States won its record 32nd Davis Cup title last year. -- AFP