<human>: Background: Patrick James Riley (born March 20, 1945) is an American professional basketball executive, and a former coach and player in the National Basketball Association (NBA). He has been the team president of the Miami Heat since 1995 and head coach in two separate tenures (1995 through 2003, and 2005 through 2008). Regarded as one of the greatest NBA coaches of all time, Riley has served as the head coach of five championship teams. He won four with the Los Angeles Lakers during their Showtime era in the 1980s, and one with the Heat in 2006.
Context: Riley played basketball for Linton High School in Schenectady, New York under head coach Walt Przybylo and his assistants Bill Rapavy and Ed Catino. Linton High School's 74-68 victory over New York City's Power Memorial on December 29, 1961, is remembered mostly for its two stars: Power Memorial's Lew Alcindor (who later changed his name to Kareem Abdul-Jabbar); and his future coach with the Los Angeles Lakers, Pat Riley. In 1991, Riley called it, "One of the greatest games in the history of Schenectady basketball."  Riley was a versatile athlete in college, participating in both basketball and football. As a junior on the 1965-66 Kentucky Wildcats men's basketball team he was named First Team All-SEC, All-NCAA Tournament Team, NCAA Regional Player of the Year, SEC Player of the Year and AP Third Team All-American, leading the Wildcats to the 1966 NCAA title game. Coached by Adolph Rupp, UK lost to Texas Western (today's UTEP), a game that was reenacted in the movie Glory Road. In his senior year Riley made First Team All-SEC, one of the only players in storied Kentucky Basketball history to make two or more First Team All-SEC teams.  He was selected by the San Diego Rockets in the 1st round of the 1967 NBA draft, and was also drafted as a wide receiver by the Dallas Cowboys in the 11th round of the 1967 NFL Draft. He joined the Rockets and was later selected by the Portland Trail Blazers in the 1970 NBA expansion draft, but was immediately traded to the Los Angeles Lakers, which he helped toward the 1972 NBA Championship both by coming off the bench in games and by guarding friend and Laker guard Jerry West in practice. He retired after the 1975-76 NBA season as a member of the Western Conference champion Phoenix Suns.  Riley finished his NBA playing career with a 7.4 points per game scoring average and a field-goal percentage of 41.4%. CANNOTANSWER
Question: why was he traded?

Answer:
<bot>: CANNOTANSWER