​LOS ANGELES – Ohio State being without quarterback Julian Sayin was the focal point going into the game against USC on Oct. 31, but the absence of freshman defensive back Jay Timmons might have been equally significant in the Buckeyes’ 30-18 loss.The Buckeyes conceded 338 total yards, 173 logged after the Trojans’ 15 catches, resulting in a season-high 6.8 yards allowed per play and the first 40-yard play Ohio State has given up this year.The first indicator of Ohio State’s defensive struggles appeared during the second play of the game, when USC receiver Trent Mosley turned a 1-yard pass into a 69-yard touchdown.Tight end Mark Bowman made freshman defensive back Simeon Caldwell a nonfactor in the play with a tunnel screen to create Mosley’s clear path to the end zone. Caldwell was making his first start for Ohio State, slotting into Timmons’ starting role.”We had some guys battling in there, and we had some guys playing some new spots,” Ohio State coach Ryan Day said. “But that’s the game, and guys have to step up.”Timmons missed his third game of the season with an undisclosed injury he suffered against Illinois on Sept. 26. He initially returned for the 19-15 win over Indiana on Oct. 17, and recorded a team-high seven tackles, two pass breakups and a forced fumble. However, the freshman tweaked the injury once again late in the game.”We held him off for quite a while, and wanted to really make sure he was back a couple of weeks ago for that game,” Day said. “So, he was trying like heck to get back [this week], but it’s one of those injuries where you put him back out there, he resets it again, and we start right back from zero again. So, he made some progress late in the week, but it wasn’t enough.”Day recognized the impact Timmons could have had on the game, especially as USC utilized the middle of the field to develop its long runs on short passes. Timmons has 16 tackles this season, along with a team-leading six pass breakups and two forced fumbles.But for junior safety Jaylen McClain, an Ohio State captain, missing Timmons was no excuse for the defense’s performance against USC.”He’s a big part of our defense,” McClain said. “Obviously he plays hard, he’s our nickel [back]. But at the end of the day, who’s ever in the game has to have competitive excellence.”McClain cited “a lack of focus, discipline and execution” as the main reasons Ohio State had a difficult time limiting USC’s explosive plays.In the third quarter, McClain was involved in one of Ohio State’s biggest defensive blunders of the game. After Bowman caught a 17-yard pass, he took off and avoided tackles from four different Buckeyes, including McClain, whom he hurdled near midfield. The tight end was pushed out of bounds at Ohio State’s 3-yard line, setting up a touchdown the next play to increase the Trojans’ advantage to 27-9.”That was ridiculous,” Day said. “We were going for the punchout there, but we’ve just got to get them on the ground around the 40-yard line, live to