USU lost to Colorado State University 16–14 on a controversial officiating call that cost the team a potential game-winning field goal attempt.

The Aggies also lost to New Mexico State 10–9 on a failed two-point conversion that tipped off the receiver's hands in the end zone, which would have won the game.

[2] Olsen was inducted into the State of Utah's Sports Hall of Fame in 1985, and was a member of USU's All-Century Football Team.

Olsen was declared a free agent by NFL Commissioner Pete Rozelle after the Patriots failed to pick up his option year by the deadline date stated on his contract.

[7] In the third of only four times the NFL exercised the Rozelle rule, the Patriots received as compensation a 1972 first-round selection (17th overall– traded to New York Giants for Fred Dryer) and $35,000 to recoup Olsen's signing bonus on July 22 and a third-round pick in the same draft (73rd overall–Jim White) on January 24, 1972.

[8][9][10] He suffered a second injury to the same knee after winning the starting position at right defensive tackle, but came back after five weeks to be the starter for the Rams in 1971 and 1972 next to his brother, Merlin Olsen.

Merlin and Phil played side-by-side as defensive tackles for the Los Angeles Rams in 1971 and 1972, the only time in NFL history this has ever happened.

That same season, in addition to starting more than half the games at center, Olsen blocked four kicks (a punt, two PATs and a field goal).

The Broncos beat the New York Giants 14–13 after Olsen blocked a PAT; for his efforts, he was presented with a game ball.

However, Olsen subsequently suffered a third knee injury and spent his time in Buffalo on the injured reserve unit, retiring shortly afterwards.