British No. 2 Dan Evans has been left out of Great Britain's Davis Cup tie against United States later this month.
The 23-year-old is replaced by Kyle Edmund, 19, who will compete with James Ward for a singles spot.
Andy Murray meanwhile looks likely to join Colin Fleming in the doubles but was not willing to reveal whether he will be playing in the doubles rubber for fear of exposing the tactics of first-time team captain Leon Smith.
"I don't want to give away any tactics or anything that may go into the match and selections and whatnot," said Murray.
"But I've spoken to Leon about it. We'll see when we get there."
Evans, who has played in the last four Davis Cup ties, is ranked 222 places above British No. 8 Edmund who is said to have more experience on clay, the chosen surface for the this year's San Diego tournament.
In contrast to Edmund, the more experienced Ward, 26, is ranked 165th in the world and has an 8-5 Davis Cup singles record but notably has never won a match on clay.
"Leon's obviously still keeping his options open," said British doubles No. 1 and doubles reserve Dom Inglot.
"I'm obviously going to go there and help the team in any way I can.
"If it means just hitting big serves to Andy, or whoever's playing number two singles, then I'll do that. If he needs me to step in and play doubles, then I'll be happy to do that as well.
"I'm pretty confident we can do well as a team. I think Andy can win both singles and between the three of us, Andy, Colin and myself, we're all capable doubles players. Even against the Bryans, we can go and win."
The Davis Cup tie against the USA begins on 31 January.