Young was selected Thursday by captain Jim Courier as the replacement for John Isner, the top-ranked American, who was unable to play because of an ankle injury sustained in the Australian Open.
Young was with the team as a practice player and was the highest ranked player not on the team.
The 24-year-old Young is 79th on the Association of Tennis Professionals rankings, 73 spots below Murray. Young and Murray have played three times, all in 2011, with Murray winning the two most recent matches.
Murray called Young, who is left-handed, “a tricky player.”
“He’s got good hands, he’s pretty quick,” Murray said.
Young, who will be making his Davis Cup debut, called representing his country, “something you dream about as a kid.” Murray has 16-1 Davis Cup singles record.
The first Davis Cup match at an open air baseball stadium in the U.S. will be played on a clay court in the outfield.
“I don’t play on clay much, he’s played on clay quite a bit,” said Young, who has a 1-11 record on clay courts in ATP World Tour and Grand Slam events, while Murray is 52-33.
In today’s second singles match, Sam Querrey will play for the U.S., facing James Ward.
Querrey is ranked 49th, Ward 175th. Ward was the winner in the only match between the two.
“James has played really well on this court the last few days,” British captain Leon Smith said. “I think the court suits him.”
Both of today’s matches pit the No. 1 player against the other team’s No. 2 player.
A doubles match will be played Saturday, with twins Bob and Mike Bryan, the world’s No. 1-ranked doubles team, facing Murray and Colin Fleming.
The reverse singles will be played Sunday, with the No. 1 players squaring off (Querrey and Murray), followed by the No. 2 players (Young and Ward) meeting each other in the final match.
All matches are best-of-five sets until one nation clinches the match. A revised schedule for Sunday may take place if a team clinches in the third or fourth match.
The match is being played at Petco Park to fulfill the Padres desire to have more off-season events at the stadium to increase revenues for the team and city.
This is the seventh time a Davis Cup match has been played in San Diego County and first since 2006, when the U.S. defeated Romania at the La Jolla Beach and Tennis Club. The U.S. has won all its previous matches in San Diego County.
The winner of the first-round tie will face the winner of the Argentina- Italy match in a quarterfinal April 4-6. If the U.S. wins, it would play in Argentina or Italy.