Ken Whisenhunt is saying goodbye to Philip Rivers. (Stephen Dunn / Getty Images)

Ken Whisenhunt became the Tennessee Titans coach on Tuesday and the Detroit Lions hired Jim Caldwell, leaving only the Cleveland Browns and Minnesota Vikings with vacancies as the pieces fell into place around the league.

In Whisenhunt, whose stint as San Diego Chargers offensive coordinator ended with a divisional-round playoff loss to the Denver Broncos, the Titans get a coach who took the Arizona Cardinals to the Super Bowl but whose overall record was only 45-51.

Whisenhunt’s hiring caused the Lions to scuttle their plans to fly to California for an interview and left them turning their attention to Caldwell, the Baltimore Ravens offensive coordinator who helped Joe Flacco find success during last year’s Super Bowl run. Caldwell succeeded Tony Dungy in Indianapolis and took the Colts to a Super Bowl, where they lost to the New Orleans Saints, and ESPN reports that Dungy phoned the Lions to recommend Caldwell for the job. ESPN’s Adam Schefter reported that Caldwell had been hired.

Caldwell is the second African-American head coach hired this offseason, with Lovie Smith getting the Tampa Bay job. There currently are four African-American head coaches in the league.

The Lions earlier interviewed Mike Munchak, who was fired as Tennessee’s coach. He is expected to interview today with the Browns, whose coaching search has been low-key since they made the unpopular decision to fire Rob Chudzinski after only one season. Cleveland will, according to the Denver Post, bide its time and wait until Adam Gase, the Denver Broncos’ offensive coordinator, is available for an interview. He figures to be tied up for a while with the playoffs.

The Vikings according to multiple reports are focusing their attention on Mike Zimmer, the Cincinnati Bengals defensive coordinator, and could have a deal in place later today, according to CBS Sports’ Jason LaCanfora. Zimmer would be the second member of Marvin Lewis’s staff to step up to a top job, with the Washington Redskins hiring offensive coordinator Jay Gruden as head coach last week.