- Bats Left, Throws Left
- Height 5' 9", Weight 180 lb.
Marcelino was born in Great Britain and lived there until he was 11. At age 8, he made his TV debut during a visit by Ernie Banks and Bobby Bonds to the country. Brad then moved to California, where he played his high school and college ball. He made his debut for the British national squad in Parma, Italy 1999 European Championship at the age of 17, going 5 for 16. In the 2001 European Championship, he hit .346/.433/.423 with 6 runs in 7 games, earning him a spot on the All-Tournament outfield. In the 2003 European Championship, Brad was 2 for 14 with 2 walks and a double. He spent that season in the Hoofdklasse, after signing with Almere. He hit .333/.417/.333 for Britain in the 2005 European Championship while playing error-free defense; only Ian Young had a higher average for the team or more hits. His 5 RBI were one behind team leader Aeden McQueary-Ennis.
Marcelino was Britain's worst regular in the 2007 European Championship, going 3 for 20 with 2 walks and a double for the Silver Medal winners; he split center field duties with Darren Heath. In the 2009 Baseball World Cup he competed against International powerhouses such as Cuba, Japan, Venezuela, Korea and Puerto Rico. He went 2 for 11 with two walks as a backup outfielder. Marcelino participated in the 2010 European Championship in Germany where he hit .389 for Team GB, second on the club behind Matt McGraw.
Marcelino participated in the 2011 European Championship Qualifier in Israel where Great Britain won the tournament qualifying for the 2012 European Championship in Holland. Marcelino lead Team GB with a .533 batting average, two doubles, 4 walks and a .619 OBP. He slugged .667 and scored 7 runs in five games. He had one outfield assist and no errors. He was second in the qualifier in average, tied third in slugging, led in OBP, was third in runs (one behind Aaron Hornostaj and Oren Gal), third in hits (behind Hornostaj and Eitan Maoz), tied for second in doubles (one behind Alon Leichman) and 4th in total bases (trailing Hornostaj, Maoz and tourney MVP Aeden McQueary-Ennis). He was especially productive in Britain's games against runner-up Israel, going 3 for 3 with 3 runs in the initial 8-6 win and 2 for 4 with a double and a run in the 5-2 clincher to enable Britain to advance. He was 0 for 1 in the 2013 World Baseball Classic Qualifiers and coached for Britain in the 2017 World Baseball Classic Qualifiers.
When he retired, he had participated in the most European Championships among British players (7). Through 2018, he was among British team career leaders in games (1st, 57, 20 more than McQueary-Ennis), runs (29, tied for 1st with Mark Vickers), hits (45, 2nd, 4 behind Young), doubles (5, tied for 9th with Vickers) and RBI (23, 3rd behind Young and Sam Wiley). He made the British Baseball Hall of Fame in 2018, 2 years after his father; the other inductee that year was also from a family with a prior inductee (Ron Marshall, grandfather of Gavin Marshall).
Marcelino signed with the Melville Braves in Western Australia. He also attended Cleveland Indians spring training in 2004.
Marcelino is currently Director of Baseball Operations and Baseball Camps at University of San Diego in San Diego, CA. He also is the Founder of the North County Mavericks Mavericks High School/College Prep Baseball Program.