San Lorenzo Valley High’s football team has forfeited the first five games of the 2018 season for its illegal use of equipment, the Sentinel learned Thursday.

The Cougars had been communicating with their quarterback from the sideline by using a headset, a violation of Rule 1-5-3C in the National Federation of State High School Associations’ Football Rules Book.

“SLV Football was asked earlier this week by our league commissioner (Tim McCarthy) if we were using a QB headset to call plays,” Jeff Calden, SLV’s principal and assistant football coach, wrote in an email. “We replied that we were. We were then informed that this practice was against the rules. Unfortunately, we had assumed that since we had played teams in the past few years that were using this technology, that it was legal. That was our mistake. We should have checked to make sure.”

The infraction is a big hit for the Cougars, who started the season 4-1 and had their sights set on making the Central Coast Section playoffs. The team can still make the postseason, but it won’t be through an at-large berth due to an insufficient amount of power points. It needs to win the Pacific Coast Athletic League’s Cypress Division, which only sends its champion to the playoffs.

SLV quarterback Stevie Markey posted on Twitter: “Honestly, this isn’t fair to us. We all know it. We thought they were legal and could use them, the rule was not clear and we have seen other teams use them. It’s just another thing that we have to (overcome) this year, and we will do it. #slvpride ”

The Gabilan Division, the top level of the four-tiered PCAL, receives four automatic postseason berths, the Mission Division receives three and the Cypress and Santa Lucia divisions each receive one.

“SLV Football understands and accepts the consequences of this mistake. Our goal is to move forward and to keep fighting for a league championship in the next five weeks,” Calden wrote.

The Cougars, under the direction of sixth-year head coach Dave Poetzinger, face host Santa Cruz (1-4, 0-1) on Friday at 7:30 p.m.

SLV will forfeit last week’s 26-7 win over host Pacific Grove, as well as wins over host Yerba Buena (35-0) on Aug. 31, Pajaro Valley (62-19) on Sept. 8 and Sobrato (41-0) on Sept. 15. The Cougars lost their season-opening game to Earl Wooster in Reno, 24-14.

CCS commissioner Duane Morgan wrote in an email: “I have worked with Coach Dave Poetzinger for the past 12 years. In those 12 years, Dave s been a valuable member of the CCS Football Committee, using his knowledge and experience to make CCS a better place for all student-athletes. His integrity and dedication to the educationally based athletics system, goes unquestioned. This mistake was based on his observations during the past few years and thinking this was an acceptable practice, without reviewing the NFHS rule books.”

Rule 1-5-3C

From the NFHS 2017 Rule Book:

c. The following Other Illegal Equipment:

3. Electronic communication devices used to communicate with a player except during an outside 9-yard mark conference (7- yard marks in nine-, eight- and six-player competition), including electronic signage to signal plays or information from the sideline.