USC Trojans offensive lineman Killian O'Connor shared his excitement about 2026 at media day on Aug. 3. He entered Bashor Lounge inside Heritage Hall on campus feeling the energy of this Trojans team. But now USC and coach Lincoln Riley will need to move ahead this season without him. Killian O'Connor Goes Down During Fall Practice Jul 28, 2026; Chicago, IL, USA; USC Football head coach Lincoln Riley speaks during Media Days at Hilton Chicago. Mandatory Credit: Kamil Krzaczynski-Imagn Images | IMAGN IMAGES via Reuters ConnectRiley revealed that the interior offensive lineman suffered a practice injury on Aug. 6, ruling him out for the rest of the season. The head coach described this ailment as a "non-contact freak injury" and immediately underwent surgery following the injury ordeal. "Tough blow for us," Riley told reporters in addressing the setback. "It was kind of a non-contact freak injury, honestly. Tough one for us, I think more than anything from an emotional standpoint."Riley raved about the impact O'Connor brought to the USC trenches. "Tremendous leader … one of the heartbeats of this program," Riley continued. "Tough one for the guys to see. We’ll get him fixed up and get him back here with the guys, and he’ll be a big part of this team even though he won’t be on the field this year.”Impact of Losing Killian O'Connor at USC Sep 6, 2025; Los Angeles, California, USA; USC Trojans head coach Lincoln Riley shakes hands with running back Eli Sanders (1) after a touchdown during the second half against the Georgia Southern Eagles at United Airlines Field at the Los Angeles Memorial Coliseum. Mandatory Credit: Jayne Kamin-Oncea-Imagn Images | IMAGN IMAGES via Reuters ConnectO'Connor entered his senior campaign this fall, joining a unit that brought back all five of their starters from 2025. Handing returning quarterback Jayden Maiava assurance that he can sling the football with a seasoned group handling the dirty work. O'Connor also became lauded for opening up running lanes for former walk-on running back King Miller during zone runs. Yet O'Connor was hampered by a bad knee during 2025 and he settled to play in eight games. He also endured a walk-on journey despite starring for nearby Trinity League prep powerhouse Rancho Santa Margarita Catholic and showed up as a smallish 6-1, 275-pound interior offensive lineman. But still worked his way to starter and emerged as a favorite inside the locker room. Once again, this ailment now rearranges the trenches in the land of Troy. Who Takes Over at USC Center Oxnard's Diego Velasco (2) can only watch as quarterback Andrew Maria is taken down by Ventura's Tobias Raymond during the first quarter of a Channel League opener at Oxnard High on Friday, Sept. 2, 2022. Ventura won 10-7.