As a player, he was signed as an undrafted free agent by the Kansas City Royals in 1990 and he spent five seasons in the minors with the Royals, Pittsburgh Pirates and Texas Rangers. His last season as a player was in 1997 with the independent Meridian Brakemen of the Big South League.
He became a minor league manager in 2001, guiding the Rangers rookie league team, the Gulf Coast Rangers for two seasons, their Class A affiliate, the Clinton LumberKings from 2003-2005 and the High A Bakersfield Blaze in 2007.
Subero was hired to manage the Milwaukee Brewers' AA Huntsville Stars in 2014. In 2015 Subero guided the 1st year franchise Biloxi Shuckers to the best record in the league with 79 wins, lost in the championship in game 5. Subero took the Southern League Manager of the Year honors.