As Lincoln Riley met with reporters Wednesday on National Signing Day, there were no new high school recruits to announce as future Trojans, no pending announcements or hat ceremonies to monitor.

As Riley acknowledged, USC's offseason roster rebuild was largely focused on mining the NCAA transfer portal, as the Trojans brought in 13 transfers to go along with eight high school signees (with five-star OT target Josh Conerly still pending a decision in March).

"I think in the future, I don't think the goal is to rely as heavily on the transfer portal as we have right now. I think this is a unique year, a unique situation where we're at in terms of the roster," Riley said. "We as a staff felt like this was going to be the best way to address the things that needed to be addressed. Certainly, we would like to have much more balance with the number of players that we sign out of high school compared to the transfer portal.

"I don't know that I would want to put a number on it, but we certainly, I would fully expect in the future that our class has a much higher percentage of high school players than this one currently does. But yeah, I'll be interested to see how it evolves."

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Evolve is the operative word, applicable to college football in general right now, between the surging number of players utilizing the transfer portal and the new Name, Image and Likeness implications that are now involved in prospects' recruiting decisions.

Riley was hired at the end of November, leaving him just a few weeks before the early signing period in December -- when most high school recruits now lock in their decisions -- to build a recruiting class that at the time retained only three prospects who had committed prior to his hiring.

USC would ultimately sign all eight of its HS recruits during that December period, landing a pair of five-stars in CB Domani Jackson and APB Raleek Brown, two more top-65 national prospects in WR CJ Williams and S Zion Branch, another four-star in CB Fabian Ross, three-star DE Devan Thompkins and LB Garrison Madden, and two-star punter Atticus Bertrams.

There are some foundational additions in there for the program, but in stating then that USC would likely turnover 35 or more roster spots, Riley knew much of the rebuild would have to come from the portal.

"Nobody's really going to ask how at the end of the day. It's, did you put together the best roster that you could and give us the best chance to accomplish what we came here to do? And so that's our focus right now," he said. "And as this roster builds and as we evolve we'll certainly continue to evaluate that."

USC addressed many of its most pressing needs through the transfer market, though some still exist.

But high-profile QB Caleb Williams (from Oklahoma) will plug in as the new face of the offense in reuniting with Riley; RBs Travis Dye (Oregon) and Austin Jones (Stanford) will have a chance to lead the backfield along with returning RBs Darwin Barlow and Brandon Campbell; WRs Mario Williams (Oklahoma), Brenden Rice (Colorado) and Terrell Bynum (Washington) could all be big factors in the passing game; OT Bobby Haskins (Virginia) will be the starting left tackle; LB Shane Lee (Alabama) figures to take on a starting role in the middle of the defense; CBs Mekhi Blackmon (Colorado) and Latrell McCutchin (Oklahoma) will compete for starting roles in a thin and inexperienced secondary; OLB Romello Height (Auburn) fills an urgent need at a position that returned only one other player; and DTs Earl Barquet (TCU) and Tyrone Taleni (Kansas State) address major depth issues on the interior of the defensive line.

"As far as the class, we're certainly excited about it. It's been very unique building it this way with the transfer portal obviously being in some ways the focus point of this class, certainly in terms of the number of players we've brought in at this point. And the portal has been an advantage for us -- there's really no other way to say it," Riley said. "When you're trying to really revamp a roster and fill the amount of spots we're attempting to fill, being able to have all those different mechanisms to use that fill that has been extremely valuable. It's been rapid.

"Typically, [you're] used to recruiting players for one year, two years, and all of a sudden some of these things are happening in a matter of days or a matter of weeks. To be able to get all that assembled so quickly, to build the relationships, to be able to really express to these players and families the vision of our program here at USC in a short time frame has been a challenge, but again, a lot of credit to everybody."

Riley used the word "unique" nine times during his press conference Wednesday.

He also made clear that USC's transfer portal raid is not over ...

"I would say that [we're] certainly far from done with the amount of roster flexibility that we have right now," he said. "So this is something I'm sure we'll continue all the way up through the spring and certainly into the summer as well."

To clear room for so many additions, USC has seen 17 scholarship players leave via the portal -- most who weren't going to have a significant role moving forward -- in addition to eight players who left remaining eligibility behind to pursue the NFL draft.

As for the actual operation of monitoring the transfer portal and evaluating potential targets, Riley was asked if he and his staff are checking it daily, hourly, what?

"Let's go a little bit smaller than that," he joked.

"As far as the portal, as you can imagine, things change from one minute to the next. So we have a team that's very dedicated behind the scenes that does a great job of keeping our staff informed," he said. "Again, that goes back to some of the key support staff that we hired and that structure as a whole that we put together, they've really done an outstanding job at this point."

Going into this process, Riley said there wasn't any position the staff wasn't looking for more help at through the portal.

He didn't want to specifically address the needs that still remain -- more help on both sides of the line, another OLB and perhaps another ILB come to mind -- or put numbers on how many more transfers they might take, but he reiterated the Trojans "still have a unique amount of flexibility."

That means it's likely more players will be both coming and going through the portal in the months ahead, especially after spring football as depth charts come into focus and guys see where they stand.

"And not all that has to happen for this year. Obviously, we took some older guys in the transfer portal that will have shorter careers here at USC, we get that. But also there's a future to look at as well," Riley said. "I think in this day and age again with the transfer portal and how everything's changing, I think you're constantly building all parts of your roster. You just never really get to the part where, OK, we're set at O-line, we're good there. I just don't think that will happen much anymore. I think you're constantly looking to upgrade and you've got to constantly be ready with an answer because it can change quickly both in having the opportunity to bring players in or potentially losing a player.

"So it's an ongoing process. But you see we added quite a few. I feel we got most of the positions covered on the team and I think we'll continue to add several on both sides of the ball and at all positions after spring wraps up."

Overall, like he said, it doesn't matter how they got there -- having only the 58th ranked incoming freshman class with just those eight signees but perhaps the most impressive transfer haul in the country -- Riley and his staff have indeed delivered a significant talent upgrade in a short period of time.

Caleb Williams was the No. 6-ranked overall prospect in the 2021 class, Mario Williams was the 16th and McCutchin was 79th, Lee was No. 50 in the 2019 class, Jones was No. 107 in 2019, Bynum was the No. 170 overall prospect way back in the 2017 class, Rice was the No. 185 prospect in the 2020 cycle and Dye has 3,111 career rushing and 869 receiving yards.

Riley also mentioned Lee, Dye and Jones as veterans he thinks will take on immediate leadership roles through the roster.

"I'm excited about what we've done in a short amount of time. I think it's been a very successful first couple of months," Riley said. "And I think we got some key players here, not only guys that maybe fit the bill at certain positions who can help on the field this fall, but we also got some guys that are going to play key parts on this team in terms of leadership, in terms of building the environment and culture that we want to be synonymous with USC football."

Meanwhile, Riley was asked Wednesday how the volume and quality of transfer additions has changed expectations for 2022, and he quickly clarified the reporter.

"They haven't changed. They'll have changed on the outside, but I've told you guys since Day 1, our expectations will never change," he said. "You don't bring in a staff like this and all of a sudden set the bar low. You don't do that. The bar should never be low at USC. This is one of the best programs of all-time and we feel like we've really assembled a championship staff, and regardless of one player, one recruiting class, will never cause our expectations to fluctuate.

"Our expectations were high the day we got here and they will be high every single day that we're here coaching. That will not change."

Class of 2022 HS prospects:

Five-star CB Domani Jackson (Mater Dei HS)

Five-star APB Raleek Brown (Mater Dei HS)

Four-star WR CJ Williams (Mater Dei HS)

Four-star S Zion Branch (Bishop Gorman HS/Las Vegas, Nev.)

Four-star CB Fabian Ross (Bishop Gorman HS/Las Vegas, Nev.)

Three-star DE Devan Thompkins (Edison Senior HS/Stockton)

Three-star ILB Garrison Madden (Dutchtown HS/Hampton, Ga.)

Two-star P Atticus Bertrams (Australia)

Transfer additions:

QB Caleb Williams (Oklahoma)

WR Mario Williams (Oklahoma

WR Brenden Rice (Colorado)

WR Terrell Bynum (Washington)

RB Travis Dye (Oregon)

RB Austin Jones (Stanford)

OT Bobby Haskins (Virginia)

DT Earl Barquet (TCU)

DT Tyrone Taleni (Kansas State)

LB Shane Lee (Alabama)

OLB Romello Height (Auburn)

CB Mekhi Blackmon (Colorado)

CB Latrell McCutchin (Oklahoma)