The day off was Pierzynski's second of the month, as he also didn't play in Chicago's Sept. 4 game against the Twins. He has played in 121 of Chicago's 145 games this season entering Sunday, including 108 starts at catcher.
The matchup against Twins left-hander Scott Diamond on Sunday also made manager Robin Ventura more inclined to start Flowers, who is hitting .304 against left-handers, compared to just .192 against right-handers.
"Give [A.J.] a day," Ventura said. "A.J. will be playing tomorrow. So it's just kind of one of those early days. Left-hander, get [Flowers] in there."
Ventura said right fielder Alex Rios will likely also get an off-day soon, perhaps during the team's series in Kansas City later this week.
But expect to see fewer off-days for Chicago's everyday players as the regular season -- and, more importantly, the American League Central race -- winds to its conclusion.
"Guys are tired, so you're just trying to make sure you're still strong," Ventura said.