© 2013 MLB Advanced Media, L.P. All rights reserved.

6/30/2013 4:44 P.M. ET

Epstein confident in Sveum, recognizes 'pen issues

SEATTLE -- The Cubs are approaching the halfway point of the season, and once again find themselves at the bottom of the National League Central standings.

"It's been one of those years where you watch the first seven innings, and there's a lot to be encouraged about," said Theo Epstein, Cubs president of baseball operations. "We've had some good individual performances and players taking their game to the next level.

"But if you wanted to sum up the first half, you'd say it went really well for the first seven innings," he said Sunday.

Of the Cubs' 45 losses, they've had the lead in 24 of them. The 24 losses after leading are tied for the most in the Majors with the Astros and the White Sox.

"We've had a really hard time closing out games," Epstein said. "Obviously, the bullpen has been the biggest culprit, but it's not to lay everything at the feet of the bullpen. We also have to get better opening up games. We get leads early and fall into a habit of making quick outs in the middle [of the game]."

The Cubs are 6-27 when they score less than four runs. On the plus side, they've hit more home runs than a year ago at the halfway point. They've also scored more runs and have a better team ERA. It's not quite enough to catch the Pirates, Cardinals or Reds, though.

"We're not where we want to be in the standings, and the main reason is we haven't been able to put games away or win close games, and we're giving too many games away that we should've won," Epstein said.

One of those games was June 16 when Carlos Marmol blew a three-run lead in the ninth against the Mets, who rallied for a 4-3 win. Marmol was designated for assignment on Tuesday, and the Cubs have gotten some interest in the right-hander.

Dale Sveum was criticized for even using Marmol at all, and Epstein said it's unfair to blame the skipper.

"The manager often times takes heat for things that are beyond their control," Epstein said. "We've given him an imperfect roster -- we have a lot of talented players, but it's an imperfect roster, and he's often times put in situations where he has to chose between imperfect solutions.

"He didn't want to necessarily use Marmol in certain situations, but there comes a point where other guys need rest or have already been used, or he's looking a day ahead," Epstein said. "I think it's unfair, with only partial information, to jump to conclusions about Dale's managerial ability based on using Marmol in a certain spot. Dale's steady at the helm of the ship and doing a nice job."

Epstein says chances of Cubs' trade action are '50/50'

SEATTLE -- Asked if he expected the Cubs to make a deal before the All-Star break, Theo Epstein, president of baseball operations, said Sunday the chances are "50/50."

"Judging by the amount of calls that are going on, I would say the number of pieces we potentially have available and the opportunities that might present themselves for us to get better, yeah, I'd say 50/50," Epstein said.

Matt Garza and Scott Feldman are drawing interest from teams looking for another starter, while clubs have also inquired about closer Kevin Gregg, who blew his first save in 13 opportunities on Saturday.

The interest -- and rumors -- will continue up until the July 31 Trade Deadline.

There also have been reports that teams are inquiring about Nate Schierholtz, but Epstein seems to be hard-pressed to part with the outfielder, who has moved into the No. 3 spot in the lineup.

"He's exceeded our expectations with the overall quality at-bats," Epstein said of Schierholtz. "To hit him in the three-hole, he does a nice job. He can handle different kinds of pitching, give you a tough at-bat. He's a threat to go deep if they make a mistake, runs the bases well. He's been really reliable defensively. He's done a nice job."

Last year, the Cubs were active at the Trade Deadline, dealing pitchers Ryan Dempster and Paul Maholm, plus catcher Geovany Soto, Reed Johnson and Jeff Baker.

Sweeney out four to six weeks with rib fracture

SEATTLE -- Cubs outfielder Ryan Sweeney has a fractured left rib, suffered when he crashed into the outfield wall at Safeco Field on Saturday, and he will not be able to do any baseball activities for four to six weeks.

Sweeney was injured after catching Kendrys Morales' fly ball for the second out in the third inning of the Cubs' 5-3 win.

"It's unfortunate, because we started to get things going with the offense and now we lose a big piece of that," Cubs manager Dale Sveum said Sunday. "It's unfortunate for him, too, because he's trying to get his career going and play every day. It stinks when those things happen to guys like that, who are good players and getting a chance and all of a sudden it's taken away for a couple of months."

Sweeney was batting .295, and had taken over in center field after David DeJesus sprained his right shoulder crashing into the outfield wall at Citi Field on June 14.

"The wall is harder now, because they put in a new wall," Sweeney said of Safeco Field. "It felt like a brick wall when I hit it. I grabbed my side, because I felt it jolt a little. I feel like I've hit that way before, and it wasn't that hard. It must have just hit me in the right spot. I came out of the game and was hoping I maybe bruised it and tried to swing and couldn't swing."

X-rays were negative, but a CT scan showed the fracture.

"I knew I didn't feel great, but obviously, you don't know if a bone is broken," Sweeney said.

For now, the Cubs will use Brian Bogusevic in center. Sweeney is headed to the disabled list, but the club didn't make a corresponding move Sunday. After an off-day Monday, Chicago will make a roster move prior to Tuesday's game against the Athletics. The team could add a pitcher, depending on whether the bullpen is taxed.

Sweeney was obviously disappointed.

"It's frustrating," he said. "Last year, I got a concussion when I was hitting .350. It seems like it comes at the worst time for me. I play hard, so it's not like I was out of control when I hit the wall. It was just a fluke thing."

Sveum said he'd like to have Sweeney be part of the Cubs' future.

"You hope so -- a left-handed bat, can catch the ball, a baseball player, he's done a great job," Sveum said. "You hope those kind of guys are always in your organization."

Extra bases

• The Cubs have played regular season games in 113 different ballparks, and this year, they will play their first games ever in Oakland, Tuesday-Thursday. Manager Dale Sveum grew up in Richmond, Calif., just outside of Oakland.

"It's always nice going back there," he said. "Hopefully, the clubhouse is fixed. That wasn't pretty. I was talking to [Seattle manager Eric Wedge], and they were there when it happened and it was disgusting."

The Mariners and Athletics had to share a clubhouse postgame because of problems with the septic system at O.co Coliseum.

Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.