NATIONAL HARBOR, Md. -- With a new closer in hand, the Chicago Cubs' front office has checked off the biggest box of its offseason. Now the Cubs can go about fortifying the rest of the bullpen as well as the starting staff. They aren't far off from fielding another World Series contender.

“We’re going to try and build up a ton of depth,” team president Theo Epstein told reporters Wednesday afternoon. “We’re going to try and build a really talented and deep bullpen with a lot of different options we can use in close games. Instead of three late-game options, you have five or six, then you can always like who you’re turning to in the bullpen and not feel the need to use a Hector Rondon four out of five times.”

Rondon will return to his setup role, but not before getting an apology from Joe Maddon. The Cubs manager called him after the team acquired Wade Davis to let the right-hander know where he stands. Maddon then admitted some culpability in Rondon’s late-season triceps injury.

“When a guy gets hurt like that out of the bullpen, I feel like I’m responsible,” Maddon said. “Maybe using him too much in different situations.”

Rondon pitched in five games over the course of seven days in late July before going down with the injury, which effectively reduced the importance of his role on the team. But all parties say the 28-year-old is 100 percent and ready for 2017. The Cubs' plan is to back off their main bullpen guys and rotate others evenly to maintain sharpness for what could be another long season. Plus, they’ve already committed to an eight-man bullpen to start next season.

“We have to be cognizant we rode these guys pretty hard,” Epstein said. “Joe’s managerial style is to go to those guys and to match up and use guys a lot. We played seven months last year. We want to play seven months again, so if you look at it, not all our guys made it through the year last year.”

How do the Cubs create enough depth to accomplish their goals? Epstein revealed several strategies associated with deepening the rotation as well as the bullpen.

• Unlike last season, the Cubs will prepare depth starters at Triple-A Iowa for when they’re needed in the big leagues. For example, lefty Rob Zastryzny is likely to start the season in the minors, even after an impressive stretch as a reliever in 2016.

“Guys with [minor league] options really have to force their way onto the team, or else they're valuable depth for us,” Epstein said. “Right now, we need more depth in the starting rotation than we do in the bullpen.”

Along with Zastryzny, Epstein identified Jake Buchanan, Aaron Brooks and (minor league pickup) Seth Frankoff as starters from within the organization the Cubs would like to call upon if needed. They’re looking for more from outside as well.

• Epstein didn’t dismiss the idea of taking someone in the Rule 5 draft on Thursday. Although the Cubs pick late, they have an opening for a long man, preferably a lefty. As the organization struggles with its pitching depth, as well as finding the right trade for a young arm, the Rule 5 draft is one way to replenish.

“It’s nice to do what we did with Rondon and bring in some new blood,” Epstein said.

Four winter meetings ago, the Cubs selected Rondon and eventually gave him a chance to be their closer. They wouldn’t mind doing that again Thursday, with the mindset of grooming a new arm to be an eventual starter. Epstein said there are some candidates. It might be wishful thinking, though, as Rule 5 picks must be on the 25-man roster for the entire season after they are chosen, and that might be a luxury the Cubs can’t afford.

• The Cubs have the means and patience to pick up a pitcher recovering from an injury. Greg Holland and Tyson Ross come to mind.

“Those really talented pitchers are going to be in demand,” Epstein said. “Even those coming off an injury. We’ll stay engaged with those guys, but it will have to be just the right talent ... and fit on the club.”

It makes sense, even if the Cubs don’t get a contribution from such a player until the second half. That’s when Maddon is more likely to employ six starters because the addition of Ross, for example, would feel like the Cubs made a midseason trade. They’ll explore, unless the bidding gets out of hand.

So far, the front office has taken one big step in its offseason plan: acquiring Davis on Wednesday. Now the Cubs will take the baby steps necessary to deliver a complete and deep team. Epstein said that winning or losing the last game of 2016 wasn’t going to change the team's goals for this winter: They’re going for it while maintaining fiscal flexibility for the coming years.

“The Wade Davis move is an aggressive move,” Epstein said. “I see that as an aggressive move, a move of an organization that’s aggressive to win another World Series.”