Houston Texans general manager Nick Caserio made the final call to fire head coach David Culley after one season, but said that decision wasn't taken lightly.

Culley went 4-13 in his only season with the team and the 66-year-old first-time head coach is owed $22 million for the balance of his four-year contract with the rebuilding franchise.

The totality of the firing can't be fully measured as the Texans began a search for Culley's replacement, which includes many past Caserio associates from his days with the New England Patriots.

"These decisions are always difficult," Caserio said. "Anytime you're in a position of leadership, you're put in positions that are difficult. It's never personal."

Texans owner and CEO Cal McNair made it clear Caserio ultimately decided the fate of Culley, a longtime assistant who previously served as wide receivers coach of the Baltimore Ravens.

"These decisions are difficult, but Nick believed it was necessary for the future of our organization," McNair said in a statement. "We look forward to continuing to build our roster and finding the right coach to lead us forward."

Pressing personnel matters closely follow replacing Culley on Houston's offseason priority list. A trade of franchise quarterback Deshaun Watson, who did not play a single snap for the team this season, could restock the depth chart with young talent if Caserio is able to get the haul he's shooting for of multiple first-round picks.

Caserio also announced offensive coordinator Tim Kelly was fired and the fate of the rest of the staff figures to be in the hands of the next head coach.

Former Dolphins head coach Brian Flores and Patriots offensive coordinator Josh McDaniels are thought to be high on Caserio's list of coaching candidates. McDaniels and Caserio were college teammates at John Carroll University and work associates in New England, where Flores also crossed over with the GM and front-office aid Jack Easterby. Easterby is officially the president of football operations in Houston.

Caserio said Friday he did what was best for the organization.

"It was a difficult decision, one of the hardest decisions I've made in my life," Caserio said. "(McNair) instilled in me the authority to do what's best for this organization."