Brewer (back) will begin a rehab assignment with Triple-A Iowa on Friday, Tony Andracki of Marquee Sports Network reports.
Brewer has missed the last couple weeks with a lower-back injury. Because he hasn't been sidelined long, his rehab assignment figures to be brief. Brewer has posted a 3.09 ERA and 12:4 K:BB over 11.2 innings with the Cubs this season.