Donnie Abraham, who guided Gibbs to its first district title in 2009, stepped down as coach Monday to become a defensive backs coach with the Tampa Bay Storm.
"I felt it was a good opportunity to gain more exposure as a coach," Abraham said. "This will help me grow as a coach and see what type of coach I can be."
Abraham, 37, made the decision Friday, but did not turn in an official letter of resignation until Monday.
"Donnie did a real good job with the program," Gibbs athletic director Mark Robertson said. "But we understand his situation, and we're sorry to see him go."
The job already is posted on the Florida High School Athletic Association Web site. The deadline for applications is March 12.
"We're going to move pretty quick because spring practice is right around the corner," Robertson said. "We want to do our due diligence and find the best possible candidate."
Abraham played for the Tampa Bay Buccaneers from 1996-2001 and the New York Jets from 2002-04. He finished his career with 38 interceptions and was a Pro Bowl selection in 2004. From 2005-08, he was an assistant coach at East Lake.
Abraham took the Gladiators in 2009 from Yusuf Shakir, who resigned that winter to take the head coaching job at his alma mater, Tallahassee Lincoln, which he led to a state title this past season.
In his first season, Abraham started 0-3 before winning the final seven regular-season games to clinch the district title and host a playoff game for the first time in school history. Last season, the Gladiators stumbled to 3-7.
But Gibbs had a young team and returns many of its star players, including quarterback Devontae White, running back Emmanuel Stewart and receiver Gary Simon.