Laura Robson will spearhead Great Britain'bid for Fed Cup promotion against Argentina next month.
The world No 39 leads a four-woman team for the World Group II promotion play-off in Buenos Aires, and she is joined by British No 3 Johanna Konta, No 4 Anne Keothavong and sixth-ranked Elena Baltacha.
British No 2 Heather Watson had already been ruled out of making the trip as she tries to get over a bout of glandular fever.
The match will decide who progresses to the eight-nation 2014 World Group II after Great Britain finished as joint winners of the Europe/Africa Zone Group I in February.
Captain Judy Murray said: "Of course we will miss having Heather with us in Buenos Aires but we are fortunate to have strength in depth and a great mix of youth and experience in our squad.
"This is a fantastic opportunity for GB to grab a place in World Group II and we will be doing everything we can to make that happen."
The two countries have not met in the Fed Cup since 1980 but Britain have won both matches so far and will probably go in as favourites despite playing on Argentina's favoured red clay surface.
They are yet to name a team for the match on 20-21 April, but are expected to go with world No 145 Paula Ormachea and 239th ranked Florencia Molinero as their singles representatives.