Rated as a three-star prospect by 247Sports, ESPN and Rivals … 247Sports ranks him as the No. 21 dual-threat quarterback in the national class, while ESPN slots him at No. 28 … ESPN lists him as the No. 87 overall prospect coming out of the state of California and Rivals places him 93rd … The latest quarterback to sign out of San Clemente HS, following New York Jets first-round pick Sam Darnold.
High School: Played for coach Jamie Ortiz at San Clemente HS … Threw for 2,132 yards on a 64.1 completion percentage with 23 touchdown passes as a junior … Also rushed for 392 yards and five touchdowns in 2017 … Built on an impressive junior campaign by passing for 2,328 yards and 22 touchdowns as a senior … Added 658 rushing yards on 108 carries and scored nine rushing touchdowns … Passed for 225 yards and a season-high five touchdowns in a 63-13 rout of El Toro his senior year … Completed 15 of 25 passes for 300 yards and three touchdowns one week later in San Clemente’s 35-26 victory over Capistrano Valley … Scored a 104.40 at the Nike SPARQ testing, per ESPN … Led the Tritons to 16 wins during his two seasons as the starting quarterback, including a 9-2 record in 2017 … Named first team All-South Coast in 2017 and 2018 and South Coast League MVP in 2018 … Finished his high school career with 4,658 passing yards and 47 passing touchdowns, as well as 1,165 rushing yards and 15 rushing touchdowns … San Clemente HS Scholar Athlete of the year in 2017 and 2018 … National Football Foundation Scholar Athlete in 2018 … Superintendent/Principal Honor Roll in 2017 and 2018 … Also a track and basketball athlete … Actively involved with Special Olympics and Best Buddies … Chose Oklahoma State over reported interest from Air Force, Army, Brown, Georgia and UCLA.
Personal: Born Feb. 27, 2001, in Boston, Mass. … Son of Brian and Kimberly Costello ... Comes from an athletic family as father, Brian, played football at Lehigh; mother, Kim, was on the diving team at UMass, uncle, Michael Costello, played basketball at Boston University and grandfather, Paul Costello, played basketball at St. Anslem’s College … Plans to study business.