When Imanaga returns, who leaves Cubs’ rotation?

The Cubs have done a nice job synchronizing success during the past few weeks.

While the offense has slumped lately, pitching picked up the slack and the Cubs are sitting at a season-high 16 games over .500 heading into a home series against Milwaukee.

Since May 15, the bullpen has been incredible, with a cumulative ERA of 0.89, easily the best in MLB. Chris Flexen, Ryan Pressly, Drew Pomeranz and Caleb Thielbar haven't given up any earned runs in that span.

A shake-up is coming, however. Starter Shota Imanaga and reliever Porter Hodge should be returning from injury next week.

Imanaga (hamstring strain) is scheduled to pitch for the Iowa Cubs on Friday and if all goes well, should be back in the Cubs rotation. Hodge (oblique strain) is set to make his second rehab appearance for Iowa on Tuesday, so he could be back even sooner.

An injury to someone else could pop up and make this process easier, but two Cubs pitchers will have to go soon.

It's not as easy as picking the exact plan that makes the most sense. One byproduct of having veterans in the bullpen is there isn't much flexibility. The only pitchers on the current roster who can be sent straight to Iowa are Ben Brown, Cade Horton and Daniel Palencia.

So while it's tempting to think about moving one of the starting pitchers to a relief role, the more likely scenario is either Brown or Horton being sent down.

The next move could depend on what happens this week. Brown is set to start Tuesday against the Brewers. He's had some outings where he looks like one of the best young arms in MLB, nearly unhittable, but has given up 6 or more earned runs in three of his last five starts.

Horton has been more consistent in his MLB debut. The worst of his seven outings was 4 earned runs in Detroit, followed by his best performance, nearly six scoreless innings against Paul Skenes and the Pirates last Friday.

Best suggestion: Send Brown to Iowa with the hope he learns to be more consistent, then it's possible he and Horton change places at some point.

Sending Palencia down does not appear to be in the cards, since he's taken on the closer's role and done well. Recent addition Genesis Cabrera has been solid (2.84 ERA) and gives the Cubs an extra lefty in the pen. But there doesn't seem to be any other choice — barring a new injury — than releasing him when Hodge comes back.

It's always possible Cabrera clears waivers and accepts an assignment to Iowa. If they lose him, the Cubs can take comfort in having some depth at Triple-A.

In fact, two left-handers are putting up nice numbers in Iowa. Luke Little, who has 38 big-league appearances and is on the 40-man roster, has a 1.37 ERA in Des Moines this season.

But maybe it's time for the Cubs to take a look at Riley Martin, a sixth-round pick in 2021 out of Division II Quincy University. He allowed 3 runs in his first outing for Iowa this year. Since then. he's given up 1 run in 29 innings, good for a 0.30 ERA.

Martin can hit 95 miles per hour with his fastball, so he actually throws harder than Little; and uses essentially a two pitch mix with four-seam and curveball, according to StatCast.

There are more relievers with big-league experience at Iowa. Tom Cosgrove, Jack Neely, Nate Pearson and Ethan Roberts are all on the 40-man. Keegan Thompson and Gavin Hollowell are currently on the injured list.

Having the best bullpen in MLB is a nice asset to have at playoff time, but there's no guarantee anyone in the Cubs current group will be pitching the same way in September.