Sophomores have long been a part of Sierra’s winning formula this season, but when Brandon Arreola burst around the corner and into the end zone this was something new.

Two weeks ago, Arreola was a member of the Timberwolves’ sophomore team, believing this moment — his first varsity touchdown — was still a year away.

But with No. 2 Sierra (10-1) leading No. 15 Rosemont comfortably in the fourth quarter of their Division III playoff opener, the call-up was thrust into action. He responded with a 36-yard touchdown on his only carry.

Arreola is part of a phenomenon that takes place each November, when players from the sophomore and freshmen teams are elevated to the varsity roster for the playoff push.

They are there as reinforcements, but mostly for the experience. They practice and share the locker room with the varsity players and coaches, and if they’re fortunate or talented enough, they’ll see the field.

Arreola was one of five sophomores added to the Sierra roster, which already featured three impact players from the Class of 2017: safeties Marcos Castillo, Nashon Tamiano and SeuSeu Alofaituli.

Look closely at the sidelines, the November Call-Up is happening everywhere.

No. 5 Ripon Christian (9-2), which faces No. 1 Capital Christian tonight in a D-VI semifinal, has bulked up its roster with nine underclassmen.

Across town, Manteca coach Eric Reis played three sophomores in last week’s 49-14 victory over Vanden in their D-III opener.

Running back Jose Garcia picked up 3 yards on a sweep early in the second quarter. Kameron Beamon had four carries for 13 yards and Gino Campiotti relieved Dakarai Charles and closed out the victory, the Buffaloes’ fifth straight.

All three could see the field tonight — even in a close game.

“Jose Garcia played for us and he’ll get in again,” said Reis, who called up eight sophomores and four freshmen, including his son Kyle, a 6-foot-2, 234-pound lineman.

“We say we’re one program. There’s no freshman team or junior varsity team. We have good continuity on our lower levels. If Jose is the next best guy, he deserves to play.”

Reis brought 12 sophomores along for the Buffaloes’ historic run to the CIF Division II NorCal regional bowl game last year.

Among that cast were Charles, wide receiver/cornerback Ronaldo Tijero, safety Marcus Rivas, linebacker Darrion Kitson and lineman Javon Dunn, all pivotal pieces in the Buffaloes’ 9-2 season.

“It’s huge. We want to show them the Manteca way,” Reis said. “Last year, when you have five extra weeks like we did, it’s a way to show them how we handle business. That way there are no mysteries about how things operate.”