Denver, CO -- (Sports Network) - On a day the Chicago Cubs activated catcher Geovany Soto from the 15-day disabled list, pitcher Carlos Zambrano missed a start.

Soto was placed on the DL on July 11 with a left oblique strain. The NL Rookie of the Year last season, Soto entered play on Friday hitting .230 with eight home runs and 27 RBI in 69 games.

To make room for Soto, the club optioned infielder/outfielder Micah Hoffpauir to Triple-A Iowa. Hoffpauir batted .233 with eight homers and 25 RBI in 81 games.

Zambrano was scheduled to toe the rubber for Friday's series opener against the Colorado Rockies, but was a late scratch because of lower back stiffness. The same ailment forced the right-hander to leave his last appearance on Saturday after three innings.

In 20 starts this season, Zambrano is 7-4 with a 3.35 earned run average.

Left-hander Sean Marshall replaced Zambrano on the mound.