While at Arizona State, he played in the 1975 and 1976 College World Series on teams that included future major leaguers Floyd Bannister, Chris Bando, and Bob Horner.

In his major league debut with the Angels, on September 11, 1977, against the Chicago White Sox, Landreaux threw out three base runners from the outfield.

[1] In 1979, the Angels traded Landreaux, Dave Engle, Paul Hartzell, and Brad Havens to the Minnesota Twins for Rod Carew.

[2] In 1980, Landreaux set a Minnesota record with a 31-game hitting streak, tied for the longest in the AL since Dom DiMaggio's 34 in 1949.

Usually batting 2nd in the order, he combined with leadoff man Steve Sax to give the Dodgers two formidable "table setters."