|Date of birth:||December 27, 1936|
|Place of birth:||Santa Monica, California|
|Height:||6 ft 1 in (1.85 m)|
|Weight:||187 lb (85 kg)|
|NFL Draft:||1959 / Round: 1 / Pick: 10|
Grosscup was a quarterback for the Washington Huskies in 1955. He and three of his former high school teammates left the school after their freshman season; deciding to sit out a year instead of continuing to play for the "tyranical" John Cherberg. He played at the University of Utah in 1957 and 1958, leading a passing offense that was advanced for its time. Monday Night Football analyst Al Michaels credits Grosscup for developing the shovel pass or "Utah pass", although Grosscup acknowledges that the play was used in the 1920s.
Grosscup finished the 1957 season completing 94 of 137 passes (68.6%) for 1,398 yards and 10 touchdowns. He was named a first-team All-American by Look, the Newspaper Enterprise Association, the Williamson National Football Rating, and Today and finished tenth in that year's Heisman Trophy balloting.
Selected by the New York Giants with the tenth overall pick in the 1959 NFL Draft, Grosscup would only appear in eight games in his three seasons with the Giants. His contract was purchased Minnesota Vikings in 1962, but was cut before the beginning of the season. This allowed Grosscup to return to New York, this time with the New York Titans of the American Football League. He began the season as the starter, but missed six weeks with a knee injury. Grosscup was cut on the final day of the 1963 preseason and signed with the Saskatchewan Roughriders three days later. That same year, Groscup released his first book, entitled Fourth and One.
After failing to make the San Francisco 49ers, Grossup spent the 1964 season on the Oakland Raiders' taxi squad. He was cut by the Raiders the following season and signed with the Hartford Charter Oaks of the newly formed Continental Football League.
From 1989-2003, Grosscup was the radio analyst for California Golden Bears football broadcasts. He was let go in 2004 in favor of former Cal quarterback Mike Pawlawski, despite Grosscup's willingness to continue until 2007. Since 2004 he has hosted "Post-Game at the Paragon!", a postgame radio show that is broadcast live from the Claremont Resort's Paragon Bar & Cafe after Cal football games.