CHICAGO -- Jeff Samardzija will start the first game of the Cubs' doubleheader on Saturday against the Reds, with lefty Brooks Raley expected to be added as the 26th man for the nightcap. Chris Volstad will close the series on Sunday, searching again for that elusive win.

Volstad has gone 23 straight starts without a "W," after losing on Tuesday to the Astros.

"We can't disregard his last two starts before [Tuesday]," Cubs manager Dale Sveum said before Wednesday's finale with the Astros. "There's still something there that we have to get figured out that we have to get on a consistent basis.

"I think [on Tuesday], his slider was getting hit as good as anything," Sveum said. "His sinker wasn't as consistent as it has been and he threw some flat ones that got hit, but at times he still had his sinker. It's just a matter of being consistent with that sinker and trying to get hitters to hit the top of the baseball."

Volstad had thrown eight shutout innings for Triple-A Iowa on July 27, and he posted quality starts in his first two outings back with the Cubs against the Dodgers on Aug. 4, and against the Reds last Thursday.

On Tuesday, Volstad went five innings, allowing four runs. Sveum said there has been no talk about moving the right-hander to the bullpen.

Soriano reportedly clears waivers, not keen on SF

CHICAGO -- Alfonso Soriano has reportedly cleared waivers and has been mentioned as a possible option for the Giants, but the Cubs outfielder said Wednesday he doesn't think San Francisco is a good fit.

The Giants may be looking for help following the news of outfielder Melky Cabrera's 50-game suspension.'s Jon Heyman reported Wednesday that Soriano, 36, had cleared waivers, but any deal would be pending the outfielder's approval because he has a no-trade clause. Soriano is still owed about $45 million through the end of the 2014 season.

"I saw the news [about Cabrera] -- somebody told me," Soriano said after Wednesday's game. "I feel sorry for him because he was having an unbelievable year. I don't know why people take those drugs. They know if they take something, someday they're going to get them. I don't know what the Giants want to do. We'll see."

The Cubs have not talked to Soriano about any possible deals. What does he think about going to the Giants?

"I don't think so," Soriano said. "San Francisco is not good weather to play in. We'll see what happens. I'll talk to my family. It's not my call -- I only have 50 percent of the call. It's my family, too. I'll talk to them in case [the Cubs] call."

Jackson confident work will start to pay dividends

CHICAGO -- Cubs fans may see lots of strikeouts now by Brett Jackson. The rookie outfielder sees progress.

Jackson, promoted from Triple-A Iowa on Aug. 5, entered Wednesday's game with 16 strikeouts in 28 at-bats. He totaled 158 K's in 100-plus games this season in the Minor Leagues.

In Jackson's first at-bat of Wednesday's 7-2 win over the Astros, he laced an RBI triple to knock in his first big league run. He finished 2-for-4 with a run on the afternoon.

"Every day, [hitting coach James Rowson] is challenging me," Jackson said before the game. "It doesn't change overnight. You've got some things built into your muscle memory that are hard to break. It may take a while, but I'm working every day to knock that out. I have the talent, I have the ability to be a really good hitter in this league."

Jackson, who was the Cubs' first-round pick in the 2009 First-Year Player Draft, is trying to simplify his swing, shorten his bat path and slow down some of the moving parts.

"I've always gotten away with movement, because I have really fast hands, so I could move and still catch up to balls, but it also leads to a lot of swings and misses and foul balls and a lot of strikeouts," Jackson said. "We know that's my favorite area of the game to talk about."

Jackson, 24, batted .256 at Iowa, and he admits he may have been pressing.

"Being in Triple-A and knowing how close I was caused me at times to press a little bit," he said. "Being here and having coaches who I know are behind me, working with me every day, I think it's a really good environment, positive environment so I can become the player I want to become."

It's not for lack of effort. Jackson is in the cage with Rowson every day.

"I know I can compete," he said. "Someday, hopefully sooner than later, these things we're working on will start really taking effect in the game. I think you're looking at a player who will be a big force in the lineup."

Extra bases

• Sveum interviewed for both the Cubs' and Red Sox's managerial openings last year. Does he ever wonder what might have happened had he gone to Boston?

"Not really," Sveum said Wednesday. "People think I was offered the [Red Sox] job -- it never got to that point. I was offered this job. It was never like I chose anything. I was offered the Cubs' job."

The Cubs have the longest drought without a championship of any professional team. They last celebrated a World Series in 1908. Sveum was asked if the Cubs' job was the greatest challenge in sports.

"It'll be the biggest event in sports history when we win, there's no question about that," Sveum said. "I was fortunate to be in Boston [when they won in 2004] after 86 years, and that was the biggest championship won."

Sveum did say "when."

"That's our goal," he said. "It's going to happen. That's the way I think. We're building to that goal, and that's the goal you have every day."