[3][4] He contributed to teams led by quarterbacks Jim Plunkett and Don Bunce in two of the biggest upset victories ever in the Rose Bowl, in January 1971 and 1972, respectively.

In 1974, he was named the special teams captain and by the end of the season he was a starter at left cornerback, but fractured his right ankle and foot against the Cleveland Browns, an injury that would affect him the rest of his career (three surgeries).

In 1976, he regained the starter position at left cornerback in the fifth game after Mark Washington suffered 2 concussions at the beginning of the season.

The next season, Barnes was moved to strong safety, to improve the depth after the retirement of Charlie Waters and to make room for undrafted free agent Everson Walls.

[6] Barnes was waived in August 1983 at the end of training camp, and replaced with undrafted free agent Bill Bates.

[7] On January 14, 1984, he signed with the Oakland Invaders of the USFL, reuniting with John Ralston, his former head coach at Stanford,[8] but was released before the season started.