The United States have made another last-minute Davis Cup switch, sending in Sam Querrey to face Nick Kyrgios in their must-win reverse singles rubber in Brisbane.

Jack Sock had been slated to face Kyrgios but was facing a third consecutive day of action after losing on Friday to Jordan Thompson then winning a five-set doubles match alongside Steve Johnson on Saturday.

Australia leads the World Group quarter-final tie 2-1 can progress to a semi-final date against either Belgium or Italy in September with one more win.