He attended
Sacramento City College. Riley was drafted by the
Baltimore Orioles in the third round of the draft. He dominated for the
Delmarva Shorebirds of the
South Atlantic League at age 18, having an
earned run average of 1.19 and 136
strikeouts in 83 innings pitched. It was there that his
curveball started becoming known as one of the best in the Orioles' organization at the time. He had similar success with the
Frederick Keys of the
Carolina League and the
Bowie Baysox of the Double-A
Eastern League in . He earned a callup to the Orioles in 1999, and though his ERA in three starts there was 7.36, he was still highly regarded by the Orioles due to his minor-league achievements that year.
Baseball America listed him as the Orioles' top prospect in both 1999 and . However, in 2000, he made only two starts for the
Rochester Red Wings (then the Orioles' Triple-A affiliate), giving up 11
earned runs in 7 innings. He spent the rest of that season and the season recovering from his first
Tommy John surgery. He returned to playing in , but with little success. He went 4-10 at Bowie, with an ERA of 6.34. He showed signs of improvement in , going a combined 9-4 for Bowie and the Orioles' new Triple-A team in
Ottawa and earning another callup to the major leagues, where he earned his first career
win and had a 1.80 ERA in two starts. The season was the first season that he began in the majors, but he struggled there. In 14 appearances (13 starts), he logged a 3-4 record and a 5.62 ERA, and he was also sent back to Ottawa for ten starts. Finally, in , the Orioles traded him to the
Texas Rangers during
spring training for
Ramon Nivar. He was able to play briefly in the major leagues for Texas, but as a one-out
middle reliever rather than a starter. He accumulated an ERA of 9.95 over seven games and was then sent down to the Triple-A
Oklahoma RedHawks. In July 2005, he had his second Tommy John surgery and missed the rest of the 2005 season. While attempting to come back from that surgery, he retore his ulnar collateral ligament and had to have a third Tommy John surgery on his left elbow. In , Riley played for the
Las Vegas 51s and
Jacksonville Suns in the
Los Angeles Dodgers minor league system. Riley was released by the Dodgers on July 24, . After not playing baseball in 2009, Riley played for two independent league teams in 2010 — the
Orange County Flyers and the
York Revolution. He then retired from the game. ==Personal life==