The two-hour bus ride was determined to be too much for Piniella to handle.
Piniella was going to watch left-hander Tom Gorzellany in his final attempt to make the starting rotation out of spring training.
On Friday, Piniella and the Cubs will announce their rotation for the beginning of the 2010 season.
Bench coach Alan Trammell will replace Piniella in the dugout.
Bruce Levine covers baseball for ESPNChicago.com.