Question: Which Colombian retired footballer who played as a striker born in 1968 hampered Orlando Maturana from joining the national team?

Context paragraphs:
Alexander Viveros: Alexander Viveros Sánchez (born 8 October 1977) is a Colombian retired footballer who played as a left back.

Luis Amaranto Perea: Luis Amaranto Perea Mosquera (born 30 January 1979) is a Colombian retired footballer.  Gifted with incredible stamina and pace, the central defender could also be adapted at right back.

Hugo Lóndero: Hugo Horacio Lóndero Secullini (born 18 September 1946) is an Argentine-born Colombian retired footballer.  He is the second top goalscorer of the Colombian Primera A with 211 goals.  He played for Colombia at 1975 Copa América, and scored one goal in an unofficial match against Brazil.

John Harold Lozano: John Harold Lozano Prado (born 30 March 1972) is a Colombian retired footballer who played mainly as a defensive midfielder.

Robinson Rentería: Luis Robinson Rentería Cuesta is a Colombian retired footballer who played as striker.  Best known for his prolific goal tally of 19 goals in the 2006-07 Venezuelan Primera División season.

Luis Carlos Perea: Luis Carlos "Coroncoro" Perea (born 29 December 1963 in Turbo) is a Colombian retired footballer who played as a central defender.

Adolfo Valencia: Adolfo José Valencia Mosquera (born 6 February 1968) is a Colombian retired footballer who played as a striker.

Edwin Congo: Edwin Arturo Congo Murillo (born 7 October 1976 in Bogotá) is a Colombian retired footballer who played as a striker.

Orlando Maturana: Maturana made several appearances for the senior Colombia national football team, including four matches at the 1993 Copa América.  He officially represented the Colombian national football team in 6 occasions.  He also made several appearances for the Colombian national team in unofficial games, most notably in 1993 against Bayern Munich and Palmeiras.  Orlando Maturana was a prolific and creative goal scorer who earn a reputation as a poacher.  His success in the national team was hampered by the availability of several more successful strikers such as Iván Valenciano, Antony de Ávila, John Jairo Trellez, Víctor Aristizábal, Luis Zuleta, Faustino Asprilla, Adolfo Valencia, and several other members of what is known today as the Colombian dream generation.

Víctor Aristizábal: Víctor Hugo Aristizábal Posada (born 9 December 1971 in Medellín, Antioquia) is a Colombian retired football striker.  Aristizábal scored 15 goals in 66 games for the Colombia national team between 1993 and 2003.

Supporting paragraphs: Orlando Maturana Adolfo Valencia
Answer: Adolfo Valencia