Farmer went down during Tuesday's spring practice in non-contact drills tearing his ACL. He is scheduled to undergo surgery within the next two weeks.
This the latest injury for Farmer, now a junior, who spent time sidelined during both his freshman and sophomore seasons with multiple injuries.
Farmer graduated from Gardena (Calif.) Serra high school as a Scout.com five-star receiver in 2011, the No. 3 ranked receiver in the country. He was the high school teammate of Robert Woods and Marqise Lee – both of whom have made historic careers for themselves at USC.
Lee said after Thursday's practice that despite the news his teammate will miss the entire 2013 and be forced to redshirt, Farmer remains hopeful he can salvage the final two years of his Trojan career.
"He is upset he isn't going to be able to play this season," Lee explained. "But from me talking with him, his mindset is great. He just told me it's another bump in the road and that's really about it."
"You feel really bad for the kid," said USC head coach Lane Kiffin. "It seems like something happens every time he's making a turn and unfortunately this one is very serious."
Farmer was positioning himself this spring to win the third spot in the receiving rotation, behind Lee and sophomore Nelson Agholor.
""Obviously we don't like it from a production standpoint for our offense because he was doing so well," Kiffin said. "He is so different from anybody on the team because, as we've said before, they don't make many guys that big that fast."
Despite Farmer's positive outlook, Lee says there's no doubt the past few seasons have been a nerve-wracking experience for the student-athlete, "I mean things happen for a reason, that's what people say…" Lee said. "It's a sad story but I'm pretty sure he'll come back even stronger than what he was."
With receiver Robert Woods leaving early for the NFL and Farmer unable to play in 2013, a Serra receiving tandem at USC may never happen again. If Lee announces for the NFL after this season, which is entirely expected, it means him and Farmer -- despite being in the same recruiting class -- will never see significant time on the collegiate field together. "Maybe, hopefully, with gods will we can play on the same team in the [NFL]," Lee said.
Farmer has five catches for 49 yards and five carries for 15 yards in his Trojan career.