CONCORD -- The Clayton Valley Charter High football team will not be able to play its scheduled season-opening game after a Diablo Valley Athletic League panel found Monday that the Eagles conducted three illegal practice sessions and an illegal scrimmage earlier this month.

The panel found that Clayton Valley held illegal practices June 2-4, also conducting an 7-on-7 passing scrimmage against Diablo Valley College without first receiving special permission from North Coast Section commissioner Gil Lemmon. The panel stripped Clayton Valley of six practice days before the start of the 2014 season, meaning the Eagles can begin practice Aug. 18 instead of Aug. 11.

By NCS rule, teams must have a minimum of 14 practice days before they open their seasons. Clayton Valley will not have enough time to meet that standard before its first scheduled game against Carson-Carson City (Nev.) on Aug. 30 at Del Oro High in Loomis.

Clayton Valley can still play 10 regular season games this year if it can find a team to play against during its scheduled bye in the first weekend of October.

The panel of three DVAL principals also put Clayton Valley on probation for one year, during which time the school must demonstrate that coaches are being instructed on the NCS rules.

Eagles coach Tim Murphy said Monday he thought the summer period began after Clayton Valley's school year ended May 30, but by NCS rules, summer drills can't start until after the final California Interscholastic Federation competition of the spring season. The state track meet ended the season on June 7, which meant football teams could not begin drills until June 9.

"We thought when school was out that we are allowed to start football. That's what it's been," Murphy said. "When our school used to get out on June 14, it would just naturally fall that way."

NCS schools Moreau Catholic, which is in the Mission Valley Athletic League, and Middletown also held illegal football practices and face sanctions by their leagues, according to DVAL commissioner Craig Lee. MVAL commissioner Tom Breen said Monday no decision has been made regarding Moreau Catholic.

Murphy said the football team's summer football schedule has been on the school's website for two months and forms were posted at the school.

The DVAL ruling was based on NCS Bylaw 103H, which states that (teams) must forfeit more days of practice than they gained by starting early. The drill against DVC added extra time to the sanctions.

Murphy hoped the league would take away "like" practice days over the summer, instead of cutting into vital practice time in August when the season is disrupted.

"I'm not trying to blame anyone but me," Murphy said. "Bottom line is it comes down to me, but it was not something we were trying to sneak around or gain an advantage from."

There appears to be confusion in the section about rules relating to practices, especially relating to school-year schedules, which can vary from district to district, and state event dates.

Even Lemmon, thinking that the June 4 state golf tournament ended the spring season, mistakenly gave James Logan permission to host a 7 on 7 passing tournament on June 7 at Laney College. When he realized his mistake, he changed the start of the summer season to June 5, according to the DVAL.