TAMPA, Fla. — Dirk Koetter is confident the Tampa Bay Buccaneers are on the verge of becoming relevant again.

The long-time NFL assistant became the team’s fifth coach in eight years Friday, assuming the task of transforming a team that has finished last in its division five consecutive seasons into playoff contenders.

Koetter, an offensive coordinator for three clubs over the past nine years, succeeds Lovie Smith, who was fired last week after going 8-24 in two seasons.

“It’s one of the happiest days of my life, but also one of the most humbling. Long time in the making,” he said, choking back tears while giving thanks to his parents for the role they played in a self-described long journey from his hometown of Pocatello, Idaho, to his first NFL head coaching position.

“I know I can do the job, even though I’m whimpering around up here a little bit. ... I’m ready it,” Koetter added. “But nothing that’s said here today will affect us one bit in wins and losses. That all comes later. There’s a lot of work to be done to get to the wins and losses part.”

Koetter’s selection wasn’t a surprise. He helped No. 1 overall draft pick Jameis Winston become just the third rookie in NFL history to throw for 4,000 yards this season and was identified by general manager Jason Licht as a “very strong candidate” when Smith was dismissed with two years and $10 million left on his contract.

The Bucs went 6-10 this season, missing the playoffs for the eighth straight year.

“We wanted a leader who could get the most out of his players. We wanted an experienced teacher ... and most importantly we wanted someone who would establish a winning culture that eventually would bring championships to Tampa,” Licht said. “Dirk Koetter was all those things.”

Licht also interviewed Arizona Cardinals offensive coordinator Harold Goodwin and Carolina Panthers defensive coordinator Sean McDermott as potential replacements for Smith, who lost his job — in part — because of an inability to fix the team’s defense.

Koetter joined the Bucs last winter and helped transform one of the NFL’s least productive offenses into one that gained more yards than any in franchise history. His first order of business as coach was hiring a defensive coordinator, selecting former Atlanta coach Mike Smith.

“Experience counts a ton in this league. The NFL is an experience league,” said Koetter, who worked with Mike Smith, when the former Falcons coach was defensive coordinator in Jacksonville and later as Smith’s offensive coordinator in Atlanta.

“To get a coach with Mike’s experience, not only as a defensive coordinator, as a teacher, as a head coach but as a man, as the right kind of guy we want in front of our players every day, I couldn’t be happier,” Koetter added.

The Bucs finished fifth in total offense, with Winston joining Cam Newton and Andrew Luck as the only quarterbacks since the 1970 NFL/AFL merger to throw for 4,000 yards as rookies. Doug Martin, meanwhile, rebounded from a pair of subpar seasons to be the league’s second-leading rusher with 1,402 yards.

Koetter led top 10 offenses in Jacksonville and Atlanta before moving to the Bucs. While this is his first opportunity as an NFL head coach, the 56-year-old was head coach at Boise State from 1998-2000 and at Arizona State from 2001-06.

Tampa Bay improved by four wins this season, but the team plummeted out of playoff contention while finishing on a four-game losing streak. The Bucs last earned a playoff berth in 2007 and haven’t won a postseason game since their Super Bowl run 13 years ago.

“This team is headed in the right direction,” Koetter said, noting that’s he’s inheriting a “really good” nucleus of talent.

“Everybody is excited and we feel like we got the right guy,” four-time Pro Bowl defensive tackle Gerald McCoy said. “If we were going to replace Coach (Lovie) Smith we picked the right person and everybody is excited. He won’t have to worry about what’s going on internally. He’ll definitely have the support of us.”