One common thread through Lincoln Riley's rapid rise as one of college football's top offensive minds, from the earliest roots at Texas Tech on through East Carolina, Oklahoma and now here at USC, has been Dennis Simmons.

When Riley stunned the football world and especially the Sooners in taking the USC job two and a half months ago, generating plenty of questions and curiosity, he didn't have to explain much to Simmons to convince him to be at the regional airport the next morning before dawn for the flight to Los Angeles.

"The friendship and the brotherhood that Lincoln and I share is one of a very strong bond," Simmons said last week. "So when he called, there really wasn't much more discussion that was needed. 'Hey, this is what I'm doing, I need you there.' So it was like, 'What time and where?'"

Said Riley, while appearing on the Jim Rome Show earlier this week: "That's my guy, man. He's a phenomenal coach, our assistant head coach, a guy that again I trust as much as you can. We've been through a lot together and he brings so much more to our team than just being an outstanding receiver coach. He's a father figure to our guys, a huge part of creating our culture, somebody I lean on for every single big decision that comes across the desk, so wouldn't do it with anybody else."

All of that is to say that Simmons is a pivotal figure in trying to make USC's offense looks like the high-scoring, prodigious Oklahoma units of recent vintage.

He holds the titles of assistant head coach, offensive passing game coordinator and outside receivers coach, and he's now in charge of the unit that got the biggest offseason shakeup.

Star wide receiver Drake London is off to the NFL, projected as a first-round draft pick, leaving a void of production behind.

Among the receiving returning, there's Gary Bryant Jr. (44 catches for 579 yards and 7 TDs last season), Tahj Washington (54-602-1), Kyle Ford (19-252-2) and a lot of unproven inexperience.

Michael Jackson III saw limited opportunities as a four-star freshman last fall, fellow four-star newcomer Kyron Ware-Hudson was slowed by a hamstring injury that kept him out of the mix most of the season, senior John Jackson III has 4 career catches and that's the list, with Joseph Manjack transferring to Houston and Bru McCoy also in the transfer portal.

Then there are the newcomers, which is the source of so much intrigue at the position.

In Mario Williams (via Oklahoma), Brenden Rice (Colorado) and Terrell Bynum (Washington), the Trojans added three transfers who could all factor heavily into the passing game. In four-star Rivals100 prospect CJ Williams, they signed their only incoming freshman WR this cycle and one who is advanced enough to factor into the depth chart competition right away.

Mario Williams was the obvious addition -- a five-star prospect and the No. 2-ranked WR in the 2021 recruiting class who signed with Riley and Simmons at Oklahoma, caught 35 passes for 380 yards and 4 TDs as a freshman and then hopped in the transfer portal to rejoin his former coaches (and QB) here in Los Angeles.

He was used mostly out wide for Oklahoma, though his elite speed allows for some creativity when putting him in motion. He would seem to make Washington redundant in the offense, but that will all shake out in spring.

It seems likely Williams will be a primary focal point in the USC passing attack this year.