PITTSBURGH -- Third baseman Ian Stewart was scratched from Friday's lineup because of soreness in his left wrist, a situation that has been nagging him this season.

Stewart, who was batting .197 overall and .233 this month, was limited to 48 games last season with the Rockies because of injuries to his wrist and knee.

Stewart has not played since Monday, as the Cubs faced two left-handed pitchers in Houston. Manager Dale Sveum said that Stewart will be re-evaluated on Saturday.

Sveum makes some moves in batting order

PITTSBURGH -- Manager Dale Sveum didn't pick a new lineup out of a hat, but he may try that next to kick-start the Cubs' offense.

On Friday, Starlin Castro was moved from No. 3 to No. 2 for the first time this year, and Joe Mather, who entered the game hitting .278, made his 12th start and his first batting third.

Castro was the Cubs' leadoff man in 72 games last season, hitting .327 with a .370 on-base percentage, eight home runs, 15 doubles and 31 RBIs. He hit second in 42 games (.335) and third in another 42 (.225).

This season he's batting .313 overall, .341 with runners on and .316 with runners in scoring position, but he's been striking out more, with 31 Ks in 44 games. Last season he struck out 25 times in 52 games in April and May.

"It's time," Sveum said on Friday. "[We haven't been] scoring throughout the whole season, and Mather's been as good as anybody swinging the bat, so I'm going to give him a little opportunity to see what he can do.

"Like I told Castro, 'It's not a demotion, it's more shaking the team up.' He was great about it -- he was like, 'Hey, I just want to win, I don't care where I hit in the lineup.' He took it well and completely understood."

Mather started in center field -- he's also played third base and left field.

"I'm going to give him an opportunity to see if he can spark us and drive the ball," Sveum said. "He's really carried over from Spring Training, and it's an opportunity for him. The limited time he's played off the bench, he's swung the bat well, and I think he's got nine walks off the bench. He's always been a real good outfielder."

The Cubs would like to see a little more pop out of the No. 3 spot in the lineup. Castro has hit two home runs; only the Phillies have had fewer from that spot (one).

"[Castro] is hitting .350 with men in scoring position, he's hitting over .300," Sveum said. "[That's] pretty good out of the third spot. You might want more home runs and quick runs that way. You take some of those balls he hit with the wind howling in [at Wrigley Field], he could have five or six home runs.

"There's nothing he's done to be put down in the two-spot. It's more change to get everything going. You never know. Sometimes you pick a lineup out of a hat and you win. I wasn't going to go that far. You can do that in the American League, not the National League."

Was he close to randomly picking a lineup?

"Not too far," he said, smiling. "You never know."

Marmol could return by early next week

PITTSBURGH -- Reliever Carlos Marmol, who has been on the disabled list since May 12 with a strained right hamstring, pitched one inning for Triple-A Iowa on Friday. The right-hander allowed a walk and a double, induced two groundouts and struck out one.

He is scheduled to pitch again on Sunday and could rejoin the big league team on Monday or Tuesday.

When he does return, he will not automatically be inserted into the closer's role, which was his job at the start of the season but has since been given to rookie Rafael Dolis.

"I think he'll still have to prove to me that he can throw strikes," manager Dale Sveum said. "It'll be the same game plan as when he was taken out of the closer's role. Nothing has changed that way."

In other injury news, catcher Steve Clevenger, who has been sidelined since April 26 with a strained right oblique, was to play nine innings for Iowa on Monday and again on Wednesday. He would then be re-evaluated to see if he is ready to rejoin the Cubs.

Reliever Blake Parker, who has been hampered by a tight right hamstring and not pitched since last Saturday, was available to pitch on Friday against the Pirates.

Extra bases

• Catcher Blake Lalli, a native of Gibsonia, Pa., just north of Pittsburgh, needed 30 tickets for family and friends on Friday. Pitcher Paul Maholm, who had spent his entire career with the Pirates before signing as a free agent this season, will start on Saturday on what was once his home turf.

"I'll try to throw a shutout no matter if it's here or Milwaukee," Maholm said on Friday.

Maholm has stayed in touch with Pirates manager Clint Hurdle, sending text messages now and then. The left-hander has been looking forward to returning to Pittsburgh, where he began his career in 2005. He never really had a chance to stay with the Pirates but said there are no hard feelings.

"I'll have fun whenever I face those guys," he said.

• The May 1 Cubs-Reds game that was rained out in Cincinnati has been rescheduled for 1:10 p.m. ET on Aug. 18 as part of a day-night doubleheader. The originally scheduled game will begin at 7:10 p.m.

Fans with tickets dated May 1 can use that same ticket at Great American Ball Park for admission to the day game; no exchange is necessary.

• The Cubs' scouting staff, led by Jason McLeod, senior vice president of scouting and player development, will gather in Chicago this weekend for the final preparations for the 2012 First-Year Player Draft, which begins on June 4. The Cubs have the sixth selection overall and two picks in the supplemental round.

"Right now the front office is focused on doing the right thing in the Draft and getting the right people," manager Dale Sveum said. "That's part of the whole plan, to build through the system. There's a lot of pressure right now to make those decisions. It's not that easy to get talent and find out the character of the talent and all of those things."

• Kerry Wood will sign copies of a new book, "All You Can Be: Learning and Growing Through Sports," on May 29 at Barnes & Noble Old Orchard in Skokie, Ill., from 7:30 p.m. to 9 p.m. CT; on May 30 at The Cubs Store at Wrigley Field 45 minutes after the game; and on June 29 at Costco, 2746 N. Clybourn Ave. in Chicago from 7 p.m. to 8:30 p.m.

This is Wood's first children's book, in which he shares valuable principles he learned growing up that helped him have success in the Major Leagues. Fourth graders from Chicago Public Schools provided drawings exemplifying their own goals, and the illustrations are included in the book. A portion of the proceeds will help support children's programs run by the Wood Family Foundation.

Wood, 34, retired last week after making one final appearance for the Cubs.