Pedro Pastor Sierra Quintana
- Bats Right, Throws Right
- Height 6' 1", Weight 185 lb.
- School Boricua College
Pedro Sierra peaked at AAA.
Sierra's father was a welterweight boxer in Cuba.  When Sierra was 16 years old, he left Cuba to play in the US, for the Indianapolis Clowns in 1954.  He then spent four years with the Detroit Stars, pitching in the 1956 East-West Game as the East triumphed. 
He was signed by Washington Senators scout Joe Cambria. In 1959, he was farmed out to the Lynchburg Senators (2-3, 3.96 in 18 G) and Sanford Greyhounds (0-1 in 2 G). He then served in the US Army for 18 months.  The Senators had become the Minnesota Twins by now and the Twins sent him to the 1962 Erie Sailors, for whom he was 8-11 with a 4.23 ERA and 10 complete games in 20 starts. He tied Jimmy Tyer for the most losses in the New York-Penn League.
With the 1963 Bismarck-Mandan Pards, he improved to 7-7, 3.96. He hit 3 homers that year and slugged .511; for a pitcher, he was a good hitter. He was 8-10 with a 4.08 ERA for the '64 Wisconsin Rapids Twins. Moving to the bullpen nearly full-time with the 1965 Thomasville Hi-Toms, he was 6-4 with a 1.75 ERA. Despite that success, he repeated with the same team in 1966, going 8-13 with a 3.70 ERA in 52 games. He tied for 2nd in the Western Carolinas League in losses and led in games pitched, 1 ahead of Don Shaw and William Seifert. Among Twins farmhands, he was 4th in pitching appearances, between Larry Bohannon and Jerry Crider.
He then went north, pitching in Canada's Provincial League. He was 14-3 for Sherbrooke in 1969.  Ted Williams invited him to pitch batting practice for the now-revived Senators and he impressed enough to sign a deal with the organization  He was 9-6 with four saves and a 3.66 ERA for the 1970 Pittsfield Senators; only Bill Gogolewski won more games for Pittsfield that summer. He was an All-Star in Panama in 1971. 
The right-hander split 1971 between Pittsfield (3-2, Sv, 5.68 in 21 G) and the Burlington Senators (1-0, 3.27 in 3 G). He then went to the Mexican League, going 14-13 with a 4.57 ERA for the 1972 Pericos de Puebla. He missed the Mexican League top-10 in wins by one. In 1973, he toiled for four different Mexican League teams (Puebla, the Diablos Rojos del México, Alijadores de Tampico and Dorados de Chihuahua (5-12, Sv, 4.57 combined).  The next summer, he was 12-10 with two saves, a 3.05 ERA and 12 complete games in 25 starts for Chihuahua and the Rieleros de Aguascalientes.  He was 0-1 with a 9.00 ERA in three games for the 1975 Rieleros to end his career after 22 seasons.
His playing career over, he went to college and began working in community service for the Montgomery County Department of Recreation, helping troubled youth for over 19 years.  He was the first Hispanic Commissioner in the Maryland Governor's Commission on Drugs and Alcohol.  He joined Essex Community College as pitching coach and remained there through 2002.  While there, he had a bit part in Major League II as a third-base coach; his uniform back can be seen in one section of the film. 
Sierra then coached for the Pennsylvania Road Warriors (2002-2003), Newark Bears (2004), La New Bears (2005) and Sussex Skyhawks (2006-2007).  In 2013, he was one of several former Negro Leaguers who got to meet with President Barack Obama.