CHICAGO -- The Cubs bullpen will get a new arm to help bridge the gap to late-inning specialists Carlos Marmol and Kevin Gregg when Jeff Samardzija is called up from Triple-A Iowa on Thursday.

Cubs general manager Jim Hendry said he would announce the corresponding move on Thursday, but the team was expected to either trade or designate for assignment right-hander Luis Vizcaino, 34. He has given up two hits and struck out three over 3 2/3 innings in four games.

"[Samardzija] will give [manager] Lou [Piniella] another option with [Aaron] Heilman getting to Marmol and Gregg, who have been throwing the ball great lately," Cubs general manager Jim Hendry said.

Samardzija struck out five over six innings in his last start for Iowa. He was called up to the big league team last July 25, and used strictly in relief, compiling a 2.28 ERA in 26 games.

"He's built his arm up," Piniella said of the former two-sport Notre Dame star. "I probably will use [David] Patton and use [Angel] Guzman a little longer. Jeff will be one of my short people -- I'm not talking about height. We'll use him an inning-plus. We'll use him about how we use Heilman."

Hendry said rumors that Cotts would be the odd man out and that Sean Marshall was being switched from the rotation to the bullpen were unfounded. Cotts has walked five and given up five hits over three innings in his eight games. Piniella gave him a pep talk after Tuesday's game.

"I told him, 'You've got a good arm, use it,'" Piniella said. "That was basically the message. [Pitching coach] Larry [Rothschild] talked to him a little about mechanics but my message was, 'You've got a good arm. If you're going to get beat, get beat with your good stuff and make the guy hit it.'"

Hendry said he was confident Cotts would get back on track.

"He had a couple bad days," Hendry said. "We'll keep giving him more chances and I think he'll be tough enough to figure it out."

Whether Samardzija will be a Major League starter or reliever has yet to decided.

"He's very versatile and mentally tough enough to switch back and forth," Hendry said. "Eventually, he'll be in one spot down the road. At this particular time, this is how we need him."

Piniella has mentioned that the Cubs still have a lot of work to do.

"A long time ago, I was taught to play 25, 30 games to evaluate where you're at," Hendry said. "The Samardzija thing is different, because I think it's a way to bridge the gap better to Marmol and Gregg and we're very pleased with the way Heilman is throwing. I don't get caught up if somebody's hitting .150 or .210 now, or somebody else is hitting .400.

"I think the guys are playing hard; they've made adjustments and won ballgames with guys not hitting or guys hurt like Milton [Bradley] was," Hendry said. "We've gotten nice lifts from people."