He played in Major League Baseball (MLB) for the San Diego Padres, Kansas City Royals, and Arizona Diamondbacks.

[2][3] On December 6, 2010, he was traded to the San Diego Padres along with Anthony Rizzo, Casey Kelly, and Eric Patterson for first baseman Adrián González.

Fuentes again opened 2013 with the Missions and raised his average to .316 with 6 home runs and 29 stolen bases in 93 games, spending time at all 3 outfield positions.

[9] After a Spring Training in which he hit .386, Fuentes was selected to be the Royals' Opening Day right fielder to start off the 2016 season, winning the spot over Jarrod Dyson and Paulo Orlando.

[12] He hit his first MLB home run on June 18, 2017, in the 10th inning of a tie game with the Philadelphia Phillies against Jeanmar Gómez; the Diamondbacks won 5–4.

[14] Fuentes spent the season with the Triple–A Reno Aces, playing in 85 games and hitting .265/.345/.394 with six home runs, 39 RBI, and 10 stolen bases.

[citation needed] In 2017 World Baseball Classic, he played center field defensively and batted ninth.