By Bruce Levine–

CHICAGO (CBS) — Improving a team that has led its division since the first day of the 2016 season should be easy enough for Cub brass. A reliever here, a left-handed bat there and perhaps another starting pitcher.

A piece of cake, right? Not exactly.

For president of baseball operations Theo Epstein and general manager Jed Hoyer, that puzzle has many moving pieces. Just getting back injured players, such as center fielder Dexter Fowler, will help inform the structure of what to add to a Cubs team that entered Friday with a seven-game division lead and 74 contests to go.

“There is always a way to improve the club,” Epstein said Friday. “All of our baseball operations department was hard at work on it during the All-Star break. Quite a few things going on but didn’t get anything done. We will continue to work hard at it over the next couple of weeks.”

Epstein and company are in a strong position to deal from position-player depth in the organization. The Cubs are in need of a left-handed reliever, and the back end of the bullpen needs to be fortified for a deep playoff run. The Yankees hold the crown jewels with just more than two weeks remaining before the non-waiver trade deadline passes, as both setup man Andrew Miller and closer may become available in the right deal.

Sitting 5.5 games out of the second AL wild-card spot entering Friday, the Yankees haven’t committed to rebuilding as of yet. However, they’re doing their due diligence and scouting the contenders’ minor league stars.

The Athletics and Rays are a pair of bottom-tier clubs that are in trade mode, and Tampa Bay had one of its top scouts at Wrigley on Friday as the Cubs hosted the Rangers.

“I don’t think its productive to pigeonhole yourself into thinking you have needs in just one specific role as the key to improving this club,” Epstein said. “There are so many variables. Things change. The way you look now may not be the way you look in mid-September. We are going to be open-minded to adding talented players knowing that could happen.”

The Cubs hope to get back Fowler by the end of this six-game homestand that runs through next Wednesday. That alone should change the dynamic of the offense. The team’s recent 6-15 slide coincided with Fowler’s hamstring injury.

As he has trade conversations, Epstein made clear he’ll listen to anyone’s ideas.

“We don’t believe in true untouchables,” Epstein said. “We do have people who seem so much a part of our core and our identity that it would be impractical to envision a deal that would make sense with them. We will always have a conversation.”

Epstein hasn’t been surprised by any recent deals, including the Red Sox acquiring quality left-hander Drew Pomeranz from the Padres on Thursday.

“We are dealing with different fronts at the same time,” Epstein said. “We are always looking to add long-term starting pitching. Sometimes the trading deadline can be a better forum for that than the offseason. Sometimes it is not. It is important to stay focused this time of year on this year’s club. You still want to keep one eye on opportunities that can help you down the road as well.”

Bruce Levine covers the Cubs and White Sox for 670 The Score and CBSChicago.com. Follow him on Twitter @MLBBruceLevine.