Rosado would have a long baseball career playing 15 years over all with just two brief appearances in the major leagues. He started out with the Marion Mets in 1972, going through A ball Visalia, AA with the Jackson Mets & reaching AAA Tidewater by 1977. After batting .275 with career bests in RBIs (59) hitting 9 HRs that year he got a September call up to the Mets.
Rosado debuted on September 8th, playing first base going 0-4 in a 8-2 loss to the Philadelphia Phillies. In his next game on September 14th he got his first career hit, coming off Hall of Famer Steve Carlton. The hit was a big one as he soon scored on pitcher Nino Espinosa's base hit. It was the only run of the game as the Mets beat Carlton 1-0.
Rosado came back with two more hits the next day including his first RBI. He would drive in two more runs that September, both in games against the Pittsburgh Pirates resulting in Met loses. Rosado played in nine games, batting .208 with a double & 3 RBIs.
Rosado appeared in just two more games with the Mets three seasons later in 1980. The next year he was sent to the Mexican League in an unknown transaction. In 1984 he signed with the Baltimore Orioles & was traded to the Detroit Tigers organization in 1985. He finally hung them up after the 1986 season.
Post Playing Days: He was the President for the Association Baseball Players of Puerto Rico for 15 years.