PHOENIX -- To freshen an overworked bullpen, the Cubs on Monday swapped one right-handed relief pitcher for another.

Chicago recalled Justin Berg from Triple-A Iowa, and to clear a spot for him on the 25-man roster, optioned fellow reliever Jeff Stevens, who has compiled a 5.71 ERA in 17 Major League appearances this season, back to Iowa.

The Cubs employed four relievers in Sunday's 14-3 loss, the first of which, Stevens, allowed four runs and three hits and three walks without recording an out in the seventh inning. He returns to Iowa for the third time this season.

Berg, who was available for the Cubs' series opener with the D-backs on Monday, made the Opening Day roster but allowed 10 earned runs in his 16 innings before he was sent down. For Iowa, the 26-year-old right-hander went 3-1 with a 3.18 ERA in 14 appearances.

-- Andrew Pentis

Zambrano to begin workouts this week

PHOENIX -- Cubs manager Lou Piniella said before Monday's game at Chase Field that he expects pitcher Carlos Zambrano to begin working out and throwing this week, but he's not sure when the volatile right-hander will be reactivated.

Piniella also couldn't say when and where Zambrano even will begin working out, only that the team would be putting together a program for him.

"We'll have some details for you tomorrow," Piniella said shortly before the Cubs opened a three-game series against the D-backs.

Zambrano was suspended for three days and has been on the restricted list since a June 25 confrontation with teammate Derrek Lee in the dugout at U.S. Cellular Field when he accused teammates of not playing behind him. Zambrano began evaluation and treatment for anger issues last week in New York with doctors selected by Major League Baseball and the Players Association. When he does return, he will be in the bullpen, not the rotation.

Zambrano, who is in the third year of a five-year contract worth $91.5 million, is 3-6 with a 5.66 ERA in 22 appearances this season, nine of them starts.

-- Barry M. Bloom

Ramirez returns as Soriano, Lee rest

PHOENIX -- Cubs skipper Lou Piniella's Monday lineup featured the return of one slugger but the absence of two others.

Third baseman Aramis Ramirez, who did not play Saturday or Sunday after aggravating his sprained left thumb -- the same injury that landed him on the 15-day disabled list June 9 -- was back in the starting lineup, slotted sixth in the batting order. He entered Monday hitting .177 with just six home runs and 23 RBIs in 55 games this season.

Piniella did elect to rest left fielder Alfonso Soriano and first baseman Derrek Lee, giving him two potent options off of the bench.

Lee and Soriano went a combined 7-for-48 (.146) at the plate during the Cubs' recent seven-game homestand. On Monday, Xavier Nady and Tyler Colvin filled in for them at first base and in left field, respectively.

-- Andrew Pentis