MILWAUKEE -- The Chicago Cubs had a rough week on the mound. In fact, it has been a rough May so far for Cubs pitching. Their team ERA is 5.36 through the first 10 days of the month.

It’s a small sample size, but the main pitchers who have been struggling are ones the Cubs need to keep an eye on. In other words, when Jon Lester is having issues, there isn’t much you can do but keep throwing him out there. He’s coming around while Jake Arrieta and Jason Hammel aren’t a concern either, especially compared to others.

But with Travis Wood, Kyle Hendricks, Edwin Jackson, Phil Coke, Zac Rosscup and a few others in a rough patch, you can’t be as sure they’ll come out of it. They either don’t have a long enough track record or haven’t had enough recent success to know. On Sunday, it was Rosscup and Jason Motte’s turn to struggle. But maybe the 5 1/3 innings of shutout ball in Milwaukee will be the corner-turning performance needed by Hendricks. We’ll see.

For now, Maddon said he’ll keep marching his back-end guys out there at the same time the team discusses options. When is enough enough? The bigger question might be where do replacements come from? The Cubs have tried several arms from Triple-A Iowa already -- such as Brian Schlitter and Gonzalez Germen -- with mixed results. That’s putting it kindly. Let’s look at the possibilities as the Cubs open a homestand with the pitching-deep New York Mets.

Trade: It’s not the time of year to acquire a major bullpen arm, at least not without way overpaying. It’s just too early for teams, save potentially a couple, to unload. A blockbuster for a starter such as Cole Hamels is not out of the question, though. A team such as the Philadelphia Phillies doesn’t need to wait until the trade deadline. If they like a deal, they’re likely to pounce on it. But at this moment, the Cubs might not be ready for that blockbuster, or the Phillies might not be ready to come off their high demands. The Cubs still need to figure out if they’re in it for the long haul this year or if they’re in "add for next season mode." A Hamels deal could pop for any team at any moment, but fixing the bullpen might have to still come from within -- at least for now.

Minors: The Cubs haven’t promoted a Double-A player right to the majors in several years, so we’ll assume any help they get will come from Triple-A Iowa. We’ve seen Schlitter and Germen, and we could see them again. The most intriguing option could be righty Blake Cooper. Cooper was acquired from Arizona when the Cubs traded former first-round pick Brett Jackson to the Diamondbacks the past summer. Cooper was a 12th-round pick of Arizona in 2010 and has given up eight hits and five walks in 14 innings this year. The knock on him was his command, but that has improved since he came to the Cubs, as his strikeout-to-walk ratio is at about 3-to-1. His 1.84 ERA and 0.89 WHIP scream major league debut at some point.

Coming into the year, prospect Armando Rivero looked like a lock to make his debut after a great 2014 season, but he’s off to a rough start, with a 5.87 ERA in 10 appearances. He won’t be up soon. After that, there isn’t a name that jumps out, so the Cubs might have to try a pitcher such as Cooper or Schlitter again. Cooper wouldn’t be the first rookie to emerge in the middle of the bullpen if he comes up.

Neil Ramirez: He was the breakout pitcher on the relief staff a year ago -- as a rookie -- but shoulder inflammation sidelined him early this season. The Cubs said he’s throwing off a mound in Arizona rather than just flat-foot tossing, so there’s progress. Using Justin Grimm’s rehab as a timeline, Ramirez could be back about a month from going down. He most recently pitched in a game April 15, so a rehab stint beginning soon isn’t out of the question, if all checks out with his shoulder.

Free agents: Any pitcher still looking for a job is probably not the answer to a contending team’s questions in the bullpen, right? Fans have asked about veteran Rafael Soriano, but word is he hasn’t looked good to other teams, so unless the Cubs see something in him no one else does, it’s doubtful he’s the guy. You never know, though, the unknown is sometimes better than the known. And anyone who has watched the Cubs knows where their problems lie, but fixing them is another story.