The Pittsburgh Steelers start their practice week with seven players on the sideline. PITTSBURGH — The Pittsburgh Steelers started preparation for the Indianapolis Colts with seven players sidelined, four of whom are dealing with injuries. Wide receiver Miles Boykin (oblique), cornerback Ahkello Witherspoon (hamstring), running back Jaylen Warren (hamstring) and center Mason Cole (foot) did not practice. All four were mentioned by head coach Mike Tomlin during his Week 12 press conference and could continue to be held out throughout the week. Tomlin didn’t shut the door on any to play against the Colts, but said Cole is the only…