"We're doing a lot of evaluation, trying to match guys up in situations where they can succeed," Sveum said. "The lineup is where we have 3-4-5 guys [Anthony Rizzo, Alfonso Soriano and Starlin Castro] and David DeJesus leading off, but other than that, it's mix and match.
"So that lineup could be different most of the time, or it could be the same for the most part against right-handers. [Josh] Vitters and [Luis] Valbuena we're going to mix and match, but we're going to give Vitters a pretty good look."
Saturday's matinee against the Rockies at Wrigley Field will also give Sveum a chance to evaluate Brooks Raley, one of the team's most promising young starters. The left-hander's contract was selected by the team from Triple-A Iowa on Aug. 7, after he was named the organization's Minor League Pitcher of the Month for July, posting a 2.12 ERA in five starts.
Raley got his first career victory in Game 2 of the Cubs' doubleheader against the Reds on Aug. 18. He tossed 5 1/3 innings and allowed four runs on five hits.
"Raley kept us in the game and did a nice job," Sveum said after the contest. "It's nice to see a guy who can get the ground balls and balls off the end of the bat with his sinker."
Meanwhile, the Rockies will send Alex White to the hill, who's looking for his first win since June 3 -- a span of nine starts.
While it's been an up-and-down season for the right-hander, White (2-6, 5.55 ERA) has lowered his ERA by nearly a point since rejoining the Rockies on Aug. 2.
In a 3-1 win over the Mets on Monday, White went four innings, allowing one run on three hits. He also struck out four and walked two but didn't receive a decision.
"Our job is to keep the team in it and hand it off to the guy behind us," White said after the game. "But our bullpen is really good, and we're doing our jobs right now, and it's helping us win."
Rockies: Chacin, Francis could be given longer leash
With Jhoulys Chacin's recent return from the disabled list, manager Jim Tracy said on Friday that he's rethinking the Rockies' 75-pitch limit for the team's starters.
While Tracy said he wasn't in position to discuss the pitching plan in detail, he said the Rockies were looking for a pitcher or two who could be given a little longer leash. Chacin -- who went six innings in Monday's 6-2 victory over the Mets -- and veteran lefty Jeff Francis are candidates for higher pitch ceilings.
Tracy said his focus is still on getting the younger pitchers -- rookie lefty Drew Pomeranz and second-year right-handers Alex White and Tyler Chatwood -- to use the pitch limit to learn to be more efficient.
"There are some learning points," Tracy said. "I know that none of these young starters that we have want to be taken out of the game after three innings. I'm OK with that. Pitch better. Pitch more consistently, and I won't take you out."
Cubs: Samardzija showing no signs of wearing down
A bright spot for the Cubs this season has been the conversion of right-hander Jeff Samardzija from a hard-throwing reliever to a reliable starting pitcher.
Samardzija's 151 2/3 innings pitched this season marks a career high during his seven seasons as a professional. However, the Cubs have no intention of shutting him down.
"He's fine," Sveum said. "We'll make those decisions, but right now -- like I said a week ago -- all of his tests came back with flying colors. Right now, we're on the thought of making it all the way through."
The right-hander tossed seven innings in Friday's 5-3 comeback win over the Rockies, allowing just three runs on six hits in a no-decision.
Cubs closer Carlos Marmol has successfully converted his last 15 save opportunities dating back to May 2.
Soriano is the only Major League left fielder to have handled at least 150 total chances without an error this season.
Rockies third-base coach Rich Dauer missed Friday's game because he will be inducted into the Baltimore Orioles Hall of Fame on Saturday, along with former pitcher Mike Mussina and longtime Orioles scout Walter Youse.