MESA, Ariz. -- It's time for the Cubs to pick the final 25.

Manager Dale Sveum, general manager Jed Hoyer and president of baseball operations Theo Epstein will be among the decision makers after Wednesday's game, as the Cubs finalize their 25-man roster.

The openings to be determined include naming a backup catcher between Welington Castillo and Steve Clevenger, finalizing the bullpen and settling on the rotation.

Ryan Dempster, Matt Garza and Paul Maholm are set as starters and Chris Volstad appears to have secured a spot. Sveum would not reveal the rest of the rotation yet. Jeff Samardzija started Wednesday against the Indians and his performance will influence the final decision.

"Performance is everything," Sveum said Wednesday. "We have decisions to make tonight and part of his performance today will have something to do with those decisions."

Samardzija was roughed up in his last outing against the Rockies, giving up seven runs on 10 hits over four innings. Sveum said Randy Wells, who will start Sunday against the Angels, and Rodrigo Lopez, who faced the Indians on Sunday, are also contenders for a spot in the rotation.

"We're just going to make our decisions tonight and see where we go with it," Sveum said. "We've got to make a decision on the long man as well and that's as much of a priority. We have 22 or 21 guys who are pretty much decided and we'll spend hopefully not more than four hours on the other four guys.

"Some people are attached to somebody and that means a lot, but sometimes you have to put your feelings aside when it comes to these decisions and what's best for the 25 guys in the organization."

Samardzija potentially locks up starting nod

MESA, Ariz. -- Jeff Samardzija may have locked up a spot in the Cubs' rotation on Wednesday.

The right-hander threw six scoreless innings against the Indians in a 2-0 Chicago victory and also showed his speed when he hit a triple.

"I feel great and obviously, we'll see what happens, but I'm not too worried about it," Samardzija said after the outing, in which he gave up three hits, one walk and struck out five.

It was a good effort after his last start against the Rockies, when he was roughed up for seven runs on 10 hits over four innings. The Rockies had loaded the lineup with lefties in that game and so did the Indians.

"It was definitely a learning experience the last time out," Samardzija said.

The difference? He threw more strikes and changed speeds. It worked.

"The last start, I was cruising through the whole spring and feeling great and I think that got to my head a little bit," Samardzija said. "I was throwing instead of really making good pitches. Today, I slowed myself down and stepped off a couple times and took a deep breath and threw the pitch that me and [catcher Geovany Soto] felt was the best pitch.

"I think we were on the same page all day today, especially the latter three, four innings," Samardzija said of his catcher. "I didn't really shake him off that much. Geo and I were right where we needed to be."

Now the question is whether Samardzija, 27, is right for the Cubs' rotation. Ryan Dempster, Matt Garza and Paul Maholm are set and Chris Volstad appears to have locked up the other opening. That leaves Samardzija, Randy Wells, Rodrigo Lopez and Travis Wood fighting for one opening. Cubs manager Dale Sveum met with the rest of the staff and the front office after Wednesday's game. Expect an announcement on Thursday.

It's been Samardzija's best spring.

"What I surprised myself with was my consistency this spring," he said. "I was in the zone and it was good pitches in the zone, not just get-me-over sliders and get-me-over fastballs. I've been throwing good location and down in the zone, and for me that excites me, because I know as the season goes along, you need to make those pitches and get quick outs.

"I'm excited to have an approach on the mound that I haven't had before and a game plan and sticking to it. I think there's still a lot left in there to tap into, but I think we'll gradually get there."

He led off the fifth with a triple and flashed some of his wide receiver speed as he rounded the bases.

"[Indians pitcher Josh Tomlin] had a great cutter all day and you couldn't pick it up," Samardzija said. "He left it over the plate a little and I kept running. It was fun. That's why I want to start. That's what I've been preaching for years. I want to be an athlete. I want to hit. I want to run the bases. I want to field my position. That's been a big part for me. To put it on paper and show I can do it means a lot to me. It was fun. I had a good time."

Samardzija pitched exclusively in relief last season. He's made it very clear how much he wants to start, but this spring, it seems he finally earned that spot in the rotation.

"I really learned a lot over the past five Spring Trainings," he said. "Being a young guy, you've got to come into camp like spring is the season. Unless you've got a six-year deal and eight years in the big leagues, nothing is for sure in camp. I didn't take anything for granted this year. I was out here early, did the same last year, and I wanted to be ready to go for camp, so I knew whatever happened, I left it all out there and was ready to go."

Mather still seeks out dad's help

MESA, Ariz. -- On Tuesday morning, Paul Mather was up early, almost before the sun was up, to help his son, Joe, with his hitting.

Joe Mather is a non-roster invitee on the Cubs who will likely find out Thursday, if not sooner, whether he made the final 25-man roster. He can thank his dad for the extra sessions.

Paul, 65, was an American Legion and high school baseball coach for 25 years before recently retiring. He now helps his son Joe, 29, who has a batting cage in his yard in the Phoenix area. Paul works with Joe on flip drills and offers pointers.

"It's such a bonus that I live here," Joe Mather said Wednesday. "He can come over and do it, and I know he loves doing it and I love having him out there. I'll do it as long as he's able and willing."

The only problem with some of the early-morning sessions in Arizona is that it's a little chilly. Joe's hands took a while to warm up on Tuesday, but he never says no.

"Any time I feel I need to do something, he'll come over," Joe said. "It's awesome."

Worth noting

MESA, Ariz. -- David DeJesus, projected as the Cubs' leadoff man, is batting .167 in 17 games this spring and the outfielder may simply be trying to impress too much.

"His numbers aren't eye-popping by any means," Cubs manager Dale Sveum said Wednesday. "I think it's a veteran guy coming into camp trying to do too much, being a little passive-aggressive maybe instead of knowing you've had a lot of success before and just go out and do it and don't worry about where you're hitting in the order or leading off or taking pitches. Sometimes, that can get you in a lot of trouble as well."

Sveum said DeJesus looks a little defensive at the plate.

"He's the ultimate professional," Sveum said. "One thing he's done is play a heck of a right field. Things aren't all that far off."

• Kerry Wood was scheduled to appear in Thursday's game in relief and not Saturday. Wood has not pitched since March 18, but there have been no physical problems with the right-hander. Wood and pitching coach Chris Bosio decided to back off this spring on innings to keep Wood fresh for the season.

• Chris Carpenter, who was sent to the Red Sox as compensation for Cubs president of baseball operations Theo Epstein, will see Dr. James Andrews on Thursday to undergo surgery to remove bone spurs from his right elbow. Carpenter announced the news himself on Twitter. He tweeted: "Stayin positive and prepared to work harder than ever to come back as soon as I can this season!" He had pitched in two Grapefruit League games.