CHICAGO -- Rodrigo Lopez has posted quality starts in each of his last three outings, but the Cubs have decided to put him in the bullpen temporarily and keep Randy Wells on schedule.

The Cubs have an off-day on Thursday and will skip Lopez, who would've gone Sunday. Instead, Carlos Zambrano (6-5, 4.78 ERA), Wells (1-3, 6.71 ERA) and Matt Garza (4-7, 3.80 ERA) will go in the weekend series against the Astros, which opens Friday.

Wells has not won a start since April 4, his first outing of the season. He went on the disabled list the next day because of a strained right forearm and hasn't found his groove since returning May 28.

"We'll take a close look at Randy and try to get him straightened out," Cubs manager Mike Quade said.

"He needs to make progress, and I'd like to see him pitch the way I've seen him in the past," Quade said of the right-hander, who had a solid spring and won the fourth spot in the rotation. "I'm hoping for as good an outing as I've seen from him in quite some time."

The Cubs also have Monday off before going on the road, and one option would've been to skip Wells and keep Lopez in the mix.

"Lopez has pitched really well," Quade said of the right-hander, who has a 1.83 ERA in his last three starts. "It's a commitment from me to Wells right now to say, 'Look, you've been a big part of this thing and keep working, but progress is important,' and so we'll do this for this Houston series."

Marmol's role daily evaluation for Quade

CHICAGO -- Carlos Marmol was available on Wednesday, but Cubs manager Mike Quade said he's still gauging how he uses the right-hander each day, depending on the amount of work he does on the side.

The Cubs are trying to get Marmol back on track. He's given up eight runs on five hits and nine walks over 5 1/3 innings in his last eight games. The time off gives Marmol more than just a fresher arm.

"I'd like to think [the time off allows for] some self evaluation and spending some time to think about what you need to do to get people out," Quade said. "I know the intensity which they've gone about it with both [pitching coach Mark Riggins] and he and Lester [Strode, bullpen coach] is important.

"If we didn't think it would benefit him, we wouldn't do it."

Quade, Riggins, Strode and Marmol then decide that day if the right-hander is available.

"If you're trying to get somebody through a tough time -- using him when they've had a long hard day of work and they're not as sharp as they normally would be -- would be so counterproductive it would be ridiculous," Quade said.

One thing hasn't changed during the extra work.

"He wants to pitch," Quade said. "Hopefully he feels better and wants to pitch today."

Cubs dealing with oppressive heat at Wrigley

CHICAGO -- Shade and water were more important than a scorecard or peanuts on Wednesday because of oppressive heat.

Neither the Cubs nor the Phillies took batting practice on the field to save their energy. The Cubs trainers were emphasizing the need to stay hydrated. The official game-time temperature was 97 degrees, but the heat index made it feel like 108 degrees.

"It'll be a tough assignment for all of them," Cubs manager Mike Quade said.

The Cubs offered water and cooling stations at each gate, and there were misters behind the left- and right-field bleacher seats.

Wrigley Field organist Gary Pressy tried to cool things off by playing "Jingle Bells" and "Let it Snow" before the game started.

An on-field thermometer near the tarp in right field registered 120 degrees.

Somehow the Phillies' Vance Worley lasted a career-high eight innings in a 9-1 victory. He got an assist from the Cubs, who created a cooling-off room between the dugout and visitor's clubhouse where the right-hander could sit. Roy Halladay didn't have that option on Monday when he had to leave the game because of the heat.

"It's only tough between pitches," Chicago's Darwin Barney said about dealing with the sweltering temperatures. "Running on and off the field was tough. When you're in the box, you don't feel it. When the pitcher starts his windup and you zero in, it doesn't bother you."

It didn't seem to bother the Phillies, who opened a 6-0 lead after three innings.

"When you're down by whatever [score], it gets hotter," Barney said. "When you're up, sometimes you can manage it better."

Hendry doesn't intend to overhaul roster

CHICAGO -- Cubs general manager Jim Hendry, in Des Moines to watch the Triple-A Iowa team, told the Des Moines Register he doesn't feel the Cubs need to overhaul the roster after this season.

"Why would we trade anybody who we think is going to help us next year or the years after?" he said.

However, the Cubs are talking to teams about improving the club.

"I would say if we move anyone it would be somebody we clearly knew wouldn't be back," he said. "We're not going to move people that we think are going to help us."

Hendry said he is not under pressure to trim payroll via trade and already has rejected several potential deals.

"Why would I trade Sean Marshall?" he said of the left-handed reliever. "Why would I trade Darwin Barney? Those calls kind of stop quickly. It makes no sense."

Extra bases

The second annual Ryan Dempster Foundation Casino Night at the Palmer House in Chicago is scheduled for Wednesday evening. Among the items to be featured in the live auction is a baseball autographed by Hall of Famer Babe Ruth.

Other items include a 2012 Ryder Cup package, including two weekly grounds passes at Medinah Country Club; a Patrick Kane autographed jersey and Blackhawks tickets; a Derrick Rose autographed jersey; and dinner with Dempster at Harry Caray's restaurant in Chicago.

Proceeds benefit the Dempster Family Foundation Strike Out 22q campaign. The foundation assists charities and organizations supporting children with 22q11.2 Deletion (DiGeorge syndrome).