Osorio made his first appearance at ATP Tour level in 1997, at his home tournament in Mexico City.

[1] As a doubles player he won two Challenger tournaments and had his best ATP Tour performance at the 1998 Legg Mason Tennis Classic in Washington, where he teamed up with Bobby Kokavec to make the quarter-finals.

[2] He played Davis Cup for the first time in 1998, when the Mexican team went to Cali to compete against Colombia and lost 2–3.

At the 1999 Pan American Games in Winnipeg he made the third round of the men's singles, but had more of an impact in the doubles competition, by claiming the silver medal.

He and partner Óscar Ortiz upset the top seeds from the United States, the Bryan brothers, in the semi-finals.