Bumped to bullpen by Cubs’ trade-deadline adds, Colin Rea gets time to prepare for possible playoff role

KANSAS CITY – The four innings Colin Rea threw Saturday might not have seemed terribly different from his usual day at the office. But for the Cubs’ righty, everything was different. Those innings came in relief. “When you’re starting, … you can have a slow build-up to the game, so you can feel your stuff out,” Rea said Sunday. “Whereas coming out of the bullpen, you’ve got to be ready to go. “You’re on from Pitch 1. There’s no easing into the game or getting a feel for stuff, like as a…