The Tigers will host the World Series champion Chicago White Sox on Monday afternoon.
Bettis, the NFL's fifth-leading rusher, closed his 13-year career two months ago with a title after Pittsburgh beat Seattle at Ford Field, which is adjacent to the Tigers' Comerica Park. The Detroit native often displays his affection for his hometown team by wearing a baseball cap adorned with an Old English D.
Detroit mayor Kwame Kilpatrick will also throw out a ceremonial first pitch to Wayne County Executive Robert Ficano.
The Contours will sing the national anthem.