This is a big summer for U.S. soccer team captain Clint Dempsey. Not only is he leading the team in his third World Cup: he is releasing his debut album.

Unbeknown to his fans and teammates, the 31-year-old Mr. Dempsey spent two weeks in Los Angeles during the off-season recording a 13-track album, "The Redux," which he and his friend, the rapper XO, plan to release in the months ahead. Using his artist name "Deuce," Major League Soccer's highest-paid player raps about going from rags to riches, "banging...