For those of you who were born after a certain date; there was an old NCAA rule in place that only allowed one school per conference to enter the NCAA tournament. USC was ranked #2 behind #1 UCLA in their conference and, because of the rule, had to sit out the tournament. Their only 2 losses came at the hands of the Bruins who went on to win their 7th title. UCLA would also win the next two years for a record 7 consecutive championships.
For USC, they were to hit the beaches early. It wasn’t until 1975 when the tournament expanded to 32 teams that the ‘one school per conference’ restriction was removed. I’m sure the 1971 USC Trojans had something to do with that change.