Kyle Edmund and James Ward are expected to play singles for Great Britain in this week's Davis Cup quarter-final against Serbia.
Andy Murray said it is "unlikely" he will play after winning Wimbledon for the second time on Sunday. But the world number two will travel to Belgrade as a spectator.
Britain's world number 73 Dan Evans will miss out with a shoulder problem.
Edmund is 67 in the world rankings, but Ward has fallen to number 240.
Murray won all eight of his singles rubbers during Great Britain's Davis Cup victory last year and contributed to 11 of their 12 points.