In 24 games (21 starts) for the White Sox, the 25-year-old Flowers has batted .227 with three home runs, 10 RBIS and an OPS of .749. Pierzynski, by comparison, had hit .288 with six homers and 40 RBIs over 110 games entering Wednesday.
"[Flowers] put himself back on the map not just for this year but next year, too," said White Sox manager Ozzie Guillen. "That's what we were waiting for."
Flowers' development has come slowly since the White Sox acquired him as one of six players in a trade with the Braves for Javier Vazquez in December 2008.
But since he was recalled from Triple-A Charlotte, Flowers has been solid in the second half for the White Sox, especially defensively.
"Now he's more hungry than he was before," Guillen said. "Signing A.J. and [Ramon] Castro back maybe opened his eyes to, 'Wait a minute, I'm getting behind.' We've been waiting for this kid for the last two years but couldn't get anything from him. Now we are."