Lester Jesus Oliveros Blanco (born May 28, 1988) is a Venezuelan former professional baseball relief pitcher. He has played in Major League Baseball (MLB) for the Detroit Tigers and Minnesota Twins. He is 6 feet 0 inches (1.83 m) tall and he weighs 225 pounds (102 kg).
Oliveros began his professional career in 2006, playing for the VSL Marlins/Tigers. That season, he went 1–3 with a 2.72 ERA in 20 games (two starts), striking out 46 batters in 39⅓ innings. In 2007, he pitched for the VSL Tigers, going 2–0 with a 1.41 ERA in 27 relief appearances, striking out 59 batters in 38⅓ innings. He moved to the United States in 2008, splitting the season between the Oneonta Tigers (15 games) and Lakeland Flying Tigers (five games), going a combined 2–3 with a 2.59 ERA. He struck out 37 batters in 31⅓ innings of work. In 2009, he pitched for the Flying Tigers (34 games) and Toledo Mud Hens (one game), posting a 4–2 record with a 4.02 ERA. Despite his inflated ERA, he managed once again to average more than one strikeout per inning, with 61 strikeouts in 56 innings pitched. He split 2010 between the Flying Tigers and Erie SeaWolves, going a combined 1–3 with a 3.65 ERA in 44 games, striking out 60 batters in 44⅓ innings.