Isaiah Casillas can be a real menace. That is a positive thing for the Murrieta Mesa football team and bad news for opposing offensive linemen and quarterbacks. Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Show Caption1 of 8Murrieta Mesa’s senior defensive lineman Isaiah Casillas. (Photo by Nick Koon, Contributing Photographer) Expand Casillas is a 6-foot, 250-pound senior defensive lineman who has racked up 175 tackles (70 for losses) and 25 1/2 sacks over the past two seasons. And his leadership this season has helped the Rams to a historic season. Murrieta Mesa is in the midst of an eight-game winning streak and has advanced to a CIF Southern Section championship game for the first time. Saturday at 7 p.m., the Rams (9-4) square off against Glendora (9-4) for the Division 6 championship at Citrus College in Glendora. “He is just so explosive. Izzy is one of the fastest guys on our defense and he’s a lineman,” said Rams coach Oscar McBride, who is in his third season in charge of the program. “He is phenomenal at the point of attack but also has an ability to chase a play down 25 yards away… He is a true see-ball, get-ball type of defender and has been an important piece to our success.” Casillas’ mother, Erin, has been battling been battling two forms of cancer, and Casillas had a decision to make last season. “I almost didn’t play because I wanted to spend more time with her,” Casillas said. “The coaching staff was great and gave me all the time I needed… It was still a really difficult year. It was hard to stay focused with everything going on, on and off of the field.” Casillas ultimately decided to play. He became an integral part of the defense and finished with 81 tackles and 13 1/2 sacks. Murrieta Mesa reached the Division 6 semifinals last season, but the program graduated several defensive starters, including linebackers Craig “CJ” Moran, Ifeanyi Onye and Luke Van den Berg and defensive end Lance Vitte. The quartet combined for 309 tackles (72 for losses) and 38 sacks last year. Casillas now was going to be the leader of Murrieta Mesa’s defensive front. Casillas has turned in another impressive campaign, as he leads the squad with 12 sacks and ranks second with 94 tackles. “This year has felt way better in many ways. I’m not sure what changed, but this is the best year I’ve ever had,” Casillas said. “I’m having fun again on the football field. I’ve bonded so much with my teammates and it’s great being out there with them.” Murrieta Mesa started this season 1-4 after playing nonleague game against the likes Tesoro, Vista Murrieta, Murrieta Valley, Valencia and Beaumont. But that schedule again prepared the Rams for another run late in the season. Murrieta Mesa won the Big West Conference’s South Division championship in unbeaten fashion before embarking on the historic playoff push. And the defense has been one of the reasons why the Rams will be playing for a section championship Saturday evening. Murrieta Mesa has allowed 11 points per game during this eight-game winning streak that includes a pair of shutout victories. The defensive unit has been exceptional from front to back, having tallied 108 tackles for loss, 53 sacks and 25 interceptions. Casillas is part of a strong defensive line that also includes Alijah Levao, Cody Morin, Noah Jenkins and Stephen Stiles. “We have so many pieces on that defensive line that it’s hard for other teams to double up on any one player,” McBride said. “And Izzy is a such a handful out there. It’s so difficult to block him one-on-one. And he’s interchangeable. We like to move him around. He might play tackle one play, nose the next and then out on the edge. He puts in the work and really leads by example.” Related Articles High School Sports | Bear Bachmeier’s return has helped Murrieta Valley football team reach Division 2 title game High School Sports | Jordan McKinney’s breakout season has Carter playing for CIF-SS football championship High School Sports | Inland teams, athletes look to shine in Fresno at CIF State Cross Country Championships High School Sports | IE Varsity’s CIF Southern Section football championship previews, Nov. 29-30 High School Sports | Inland boys basketball teams to watch during the 2024-25 season That leadership role is something Casillas has embraced. “Those were big shoes to fill,” he said. “It’s not just me, though. We have a lot of good players back who have stepped it up.” Casillas is looking forward to Saturday night’s game and possibly bringing home the program’s first section championship. “It’s my senior season and that would be a great moment,” he said. “It’s exciting, and I’m loving every single minutes of this.”