Source: Chiefs’ Muir will retire

One of the NFL’s longest-tenured assistant coaches is hanging up his whistle.

A source told that Kansas City Chiefs offensive coordinator/offensive line coach Bill Muir is retiring.

Muir, 69, completed his 34th NFL season in 2011. Muir’s other NFL coaching stops include Tampa Bay (2002-2008), the New York Jets (1995-2001), Philadelphia (1992-1994), Indianapolis (1989-1991), Detroit (1985-1988) and New England (1982-1984). His NFL career began in 1978 as a Buccaneers scout.

The Chiefs began seeking a new offensive coordinator last month when Romeo Crennel was named head coach. Former Kansas City head coach Todd Haley named Muir his offensive coordinator last season but continued to play a major role directing the team’s offense.

In other NFL coaching news, a source told that Oakland is hiring Houston’s Frank Pollack as its new offensive line coach. Pollack has served as the Texans’ assistant offensive line coach the past five seasons.