Dan Evans has been given the nod by Great Britain captain Leon Smith for this weekend's Davis Cup first-round tie against Japan.
It had been expected that Kyle Edmund would play in the singles along with Andy Murray.
However, 21-year-old Edmund has been forced to pull out with a back complaint, which has resulted in Evans's promotion.
Evans, 25, was part of the triumphant British squad that won the competition last year, although he did not feature in the final against Belgium.