Something special seems to be brewing in the USC Trojans quarterback room.

Fresh off of Caleb Williams’ Heisman Trophy win, coach Lincoln Riley has added another star passer: Malachi Nelson, considered by some — including ESPN — to be the best player at any position in this year’s signing class.

“Guys like these are very, very tough to come by. He’s the #1 QB in the nation and joins QBU and Heisman U,” the team tweeted.

Nelson, a five-star pro-style quarterback, chose the Trojans over fellow football blue bloods Oklahoma and Alabama on the sport’s de facto National Signing Day, according to 247 Sports.

“USC signing Malachi Nelson gives USC the third No. 1 recruit in the ESPN 300 since those rankings began in 2006,” noted ESPN college football writer Pete Thamel, who added that Riley has worked with five previous ESPN 300 QBs.

The Los Alamitos product has “arm strength, measurables, intangibles, and more,” said recruiting and scouting expert Billy Tucker.

Though ESPN placed Nelson No. 1 in their rankings of the top 300 recruits, 247 Sports’ composite of multiple major rankings places the new Trojan as the No. 2 quarterback and No. 3 player overall.

“It’s been in Ohio as early as the mid-1850s at least, brought in as an ornamental plant because of its unique foliage and white flowers,” Gardner said. “It was actually planted in people’s landscaping, and it has been spreading.”

Only Arch Manning, the Texas-committed quarterback who is grandson of Archie Manning and nephew of Peyton and Eli Manning, and coveted cornerback Cormani McClain are ahead of Nelson in the composite numbers.

Manning, perhaps the most hyped recruit in the sport’s history, scored a near-perfect 0.9999 rating, while McClain only edged out Nelson for the No. 2 spot by 0.0001.

Joining Nelson as part of USC’s top-15 signing class are two fellow five-stars, both wide receivers: Makai Lemon, also of Los Alamitos, and Zachariah Branch of Las Vegas powerhouse Bishop Gorman.