Lincoln Riley Rebuilt USC Through the Portal, and the Roster Churn Became His Problem

Lincoln Riley took over a USC team that finished 4-8 in 2021 and turned it into an 11-win team the next fall. He did it mostly through the transfer portal, led by quarterback Caleb Williams, who followed Riley from Oklahoma and won the Heisman Trophy in 2022. That first roster proved a coach can buy a contender in a single offseason. Riley says the fast start was just the tip of the iceberg. The three seasons since have shown what that kind of building costs, and he has changed course this year to address it.

The portal makes talent easy to add and almost impossible to hold together. A coach can sign a dozen new starters in December and field a better team in September. He cannot make those players trust each other, learn one system, or stay long enough to build the habits that decide close games. USC has lived on both sides of that trade, and the second side has shaped Riley’s tenure more than the first.

What the roster churn cost USC

The 2022 team scored on almost everyone and stopped almost no one. USC ranked among the best offenses in the country while its defense came apart, and the Trojans lost the Cotton Bowl to Tulane 46-45. The next year told the same story. Williams kept the offense elite, but the defense became one of the worst units in program history, gave up more than 34 points a game, and USC dropped five of its last six before a bowl win over Louisville.

Those defenses had plenty of talent. What they lacked, however, was time together. A front seven built from new transfers and freshmen has to learn to play together and master one scheme in the same few months, and the bill comes due in November. The pattern held, and it followed USC onto a bigger stage.

USC joined the Big Ten in 2024, and the move added cross-country travel and a tougher weekly grind to a program still learning to keep a roster intact. The Trojans went 7-6 in that first season and struggled with the intensity and the schedule after years in the Pac-12. Riley then hired defensive coordinator D’Anton Lynn, and the defense improved sharply, which reinforced his point. One steady coordinator changed more than any single portal haul ever had.

Why Riley changed his approach

This offseason, Riley ran the opposite play. USC signed the No. 1 recruiting class in the country for 2026 and added only eight transfers, a small number next to his early classes. The Trojans also returned 15 starters, the most of any Power Four program, and leaned on young players they plan to develop rather than replace. USC even began announcing returning players as re-signings, borrowing NFL free-agency language, and other programs copied the idea.

The message underneath it is plain and simple. Riley decided the churn was the problem. He built USC fast when he had to, learned that fast rosters fade late and struggle to defend, and now wants a core that stays together long enough to grow steadier. Continuity in the portal era is no longer something a program has. A coach has to protect it on purpose.

The hard part is that the Big Ten does not get easier while he works on it. USC still flies across the country most weekends, still faces a far deeper league than the Pac-12 ever did, and still coaches in a sport where a third of any roster can walk out the door every December. Riley has the talent to win in that world. Whether he can keep enough of it together, season after season, is the question that will decide how his USC will be remembered.