The Cubs have the second-best bullpen ERA in the National League, but they haven't had a designated closer in six weeks.

That doesn't look to be changing anytime soon, either.

Brandon Morrow is still nursing a sore biceps/elbow and does not currently have a timetable to return to the Cubs bullpen.

He threw from flat ground again before Wednesday's game from a distance of 105 feet. He's thrown from flat ground a few times over the last week or so, but the last time he was on a mound was Aug. 18 in Pittsburgh for a 25-pitch bullpen session. Morrow flew back to Chicago after that bullpen to get more tests on his arm, but the Cubs insisted there was no setback.

Right now, nobody knows when he will on a mound next and at this point, you can rule out any chance of Morrow pitching in a minor-league game as part of a rehab stint. The best case scenario would be a mid-September return.

"He is doing better and he's reported that he's not feeling anything after he's thrown, which is a good thing," Joe Maddon said. "We're optimisitic, but we haven't put a date down to get him on the mound or get him in a sim game. We haven't done that yet.

"We're just small victories right now that he's feeling better every time. Relatively soon, though, we're gonna have to be figuring that out. We're getting closer to having to start to figure out when's the right time to get him out there on the mound, doing regular pitching things.

"We may have to test it out and find out if it's gonna be real or not for the next month."

The Cubs have about four-and-a-half weeks left of regular season action before playoffs begin. They haven't pushed Morrow with his long injury history, nor have they really needed to with trade acquisitions like Jesse Chavez helping to augment the bullpen in Morrow's absence and keep the Cubs atop the NL Central.

With the minor-league seasons ending this week, the only way Morrow will be able to face live hitters before returning to a game is if he pitches a simulated game at Wrigley Field against his Cubs teammates.

That will become easier to do beginning Saturday when rosters expand.

The Cubs also could roll Morrow out in low leverage situations in September, working him in in the fifth or sixth inning or when they're up/down big in games.

"You'll have extra players here to start up a sim game and then you could pick and choose earlier parts of the game and almost treat it like a rehab assignment," Maddon said. "You just have to be more creative with it. Definitely worth it for a guy like that. We'll try to figure that out as well as we can."

Morrow has been exactly as advertised since signing a two-year, $21 million free agent deal over the winter.

He's served as an anchor of the Cubs bullpen and a low-stress closer, converting 22 of 24 save chances with a 1.47 ERA, 1.08 WHIP and 31 strikeouts in 30.2 innings. When he's on, he comes right out and attacks hitters, pumping strikes at a high rate without wasting many pitches or nibbling.

Morrow's been valuable for the Cubs in the regular season, but where they're gonna need him the most is in October, when elite relievers suddenly become so important. So it makes sense the Cubs have been so patient with him and this injury.

They've gotten by without him by using a mix of options in the closer's role, with Pedro Strop getting most of the opportunities.

But Maddon has not named anybody the "closer" since Morrow's been on the DL, joking this week that Strop is not the "ordained" closer — "He's not been to the Vatican," Maddon riffed.

Strop has picked up 8 saves in the second half, Chavez has notched a pair and even guys like Brandon Kintzler have come in to pitch the ninth inning after Maddon utilized Strop in the eighth to snuff out a rally (like last week in Detroit).

Whenever Morrow does return, he won't immediately be thrown right back into the closer's role, though part of that is because he won't have had much of an opportunity to face live hitters with no rehab stint.

"That would be a bad assumption for me, I think. You'd have to build him back into that role and find out where he's at," Maddon said. "And even if you want to use him in the ninth inning, I can't even imagine back-to-back nights kind of a thing.

"You would think that by the end of the month, if it all went well, that you can possibly do something like that. But I don't think that you just throw him back into that."