[3] He spent his entire Negro League career with the Grays but continued his college education in the off-seasons while also playing football and basketball.

[4] In 1940 Fields joined the Grays at the age of 17, showing records of 2–1, 13-5 and 15–3 in his first three seasons, but his promising career was interrupted —but hardly harmed— by Army service in Europe during World War II.

Later that same year, Fields led Homestead to defeat the Baltimore Elite Giants 3–0 in the 1948 Negro National League Championship.

Once the Grays disbanded, Fields received numerous contract offers from major league organizations, but he was content with what he was doing and refused them.

As a result, he travelled to Canada to play for the Brantford Red Sox of the competitive Intercounty Baseball League in southwestern Ontario.

While playing for Brantford, he posted pitching records of 11–2, 10–2, 9-3 and 8–0, and batting averages of .382, 381, .379 and .425, respectively, to win three MVP awards in the league during the 1951, 1954 and 1955 seasons.

He earned MVP honors in the 1956 NBC tournament, putting his name alongside greats such as Satchel Paige (1935), Red Barkley (1941), George Archie (1943), Cot Deal (1944–1945), Bill Ricks (1949), Pat Scantlebury (1950), Daryl Spencer (1955) and Clyde McCullough (1955).

[13] Likewise, Fields represented a good example of a ballplayer who benefited from the opportunities created by the interdependence of Latino and black baseball.

Then, he posted a 10-4 pitching record and hit .330 with 11 homers in the 1948–1949 season, topping the league with 88 RBIs and winning MVP Award honors,[1] to lead his team to the 1949 Caribbean Series.

Notably, Fields got one start in the event and defeated the highly favored Alacranes de Almendares of Cuba, 6–1, limiting them to five hits in a complete game effort.

In the previous game, facing the Navegantes del Magallanes of Venezuela, Fields belted a pinch-hit, bottom of the ninth, two-run homer against Terris McDuffie, to lift the Criollos to a 2–1 victory.

[7] After that, Fields spent time in the Venezuelan Professional Baseball League while playing for the Cervecería Caracas and Patriotas de Venezuela clubs in a span of three seasons.

He became the first player in league history to hit two grand slams in a single season, a feat only matched by Billy Queen in the 1953–1954 tournament and Pete Koegel in 1973–1974.

[17] In 1951–1952, playing full-time, Fields carried Cervecería to the pennant title en route to the 1952 Caribbean Series, winning the league's batting crown with a .357 average, while also leading in hits (74), RBIs (45), runs scored (48), and doubles (21).

At the Lorton Correctional Complex, he organized baseball games between inmates and young Prince William County players.