OAKLAND — McClymonds was supposed to face Castlemont on Saturday night in the Silver Bowl for the Oakland Section championship.

Instead, the powerhouse program will play host to Oakland Tech after section officials learned that Castlemont used an academically ineligible player in a semifinal game Friday night.

Castlemont beat Oakland Tech 27-20.

The player had improved his grades during a two-week window the Oakland Unified School District allows for missed assignments, Castlemont coach Ed Washington said. But the CIF cutoff date had already passed.

Washington said he accidentally looked at the player’s post-cutoff date grades.

“It’s on me and it’s because of a mix-up of the date by me,” Washington told the Bay Area News Group on Monday. “It’s not the kid’s fault, it’s not the school’s fault, it’s Ed Washington’s. It was literally an honest mistake and a mix-up.”

Castlemont, which lost to McClymonds in last year’s Silver Bowl, finished the season 6-5.

Oakland Section commissioner Franky Navarro said his office was alerted about the mistake on Friday night and began an investigation shortly after the semifinal game ended.

“By Saturday morning, we had concluded the investigation,” Navarro said Monday. “When an inquiry comes in, we send it over to the principal. The principal verified the information, and we made the ruling based on that.”

Navarro added about Washington, “It wasn’t like he just purposefully put someone in there” that was ineligible.

McClymonds has won the past 12 Silver Bowls, including 10 under retiring coach Michael Peters. Oakland Section officials moved this year’s game to McClymonds so that Peters could have one final home appearance against an Oakland school.

Skyline forfeited its semifinal game at McClymonds last week.

Two weeks ago, McClymonds routed Oakland Tech 40-0 and has outscored its five Oakland Athletic League opponents this season 251-0.