Air Force defensive coordinator Tim DeRuyter will be leaving the academy to become the defensive coordinator at Texas A&M, according to a source close to the situation.

An official announcement likely won’t be made until Thursday after a meeting of the Texas A&M Board of Regents.

According to the meeting agenda, available on the Texas A&M Web site, one of the “Additional Items/Reports to Be Considered by the Board” is “Authorization for the President of Texas A&M University to Execute an Employment Contract with An Assistant Football Coach-Defensive Coordinator.” According to the meeting schedule, that will be discussed during the executive session that is estimated to finish at 2 p.m. Central time.

Air Force sports information director Troy Garnhart said academy officials and coaches had no comment on DeRuyter’s status.

DeRuyter, 47, was the Falcons’ defensive coordinator the past three seasons under coach Troy Calhoun. He will replace the retired Joe Kines at Texas A&M.

Air Force assistant head coach and co-defensive coordinator Matt Wallerstedt is the likely replacement for DeRuyter at the academy. Wallerstedt, who also handles the Falcons’ inside linebackers, just completed his second season at Air Force.

A 1985 academy graduate, DeRuyter was the Falcons’ highest-paid assistant in 2009, receiving $205,000. But he will earn far more at Texas A&M.

During his tenure at Air Force, DeRuyter helped transform a porous defense. He replaced a passive, bend-but-don’t-break style with an attacking 3-4 set that was based off the Pittsburgh Steelers’ scheme. And in 2009, the Falcons’ defense was among the nation’s best.

Calhoun has kept his staff mostly intact during his tenure. Tim Horton and Brian Schneider, who Calhoun hired to be his offensive and special teams coordinators, respectively, left for other jobs before Calhoun had coached a game. And defensive assistant Brian Knorr left after the 2007 season. But DeRuyter’s departure is the most significant to date.

The year before DeRuyter arrived at the academy, Air Force ranked 78th in the country in scoring defense (25.2 points allowed per game) and 78th in total defense (354.7 yards allowed per game). The Falcons finished the 2009 season ranked 10th in scoring defense (15.7) and 11th in total defense (288.3 – the lowest mark at the academy since 1966).

DeRuyter’s final game at Air Force was a masterpiece. Facing Houston in the Armed Forces Bowl, the Falcons limited the nation’s top-ranked passing offense to a season-low 222 yards through the air and picked off highly touted quarterback Case Keenum six times.