This story was excerpted from Jordan Bastian's Cubs Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

CHICAGO -- The Cubs knew multiple question marks were hovering over their bullpen going into this season, but hoped to have some answers revealed by this point. It is nearly June, and manager David Ross is still searching for the right formula. 

“We’ve got to get that thing figured out a little bit down there,” Ross said on Sunday morning. 

That was before another rough day for Chicago’s pitching staff, which yielded 25 runs to the Reds during a disappointing three-game sweep. Three abbreviated starts made things harder on the relief corps, which has logged an 8.05 ERA in the past 14 games. 

No one is expecting Codi Heuer to return from the injured list as some sort of bullpen savior, but Ross is looking forward to adding another experienced arm to the mix. June was always the target for Heuer’s comeback from Tommy John surgery, and the righty looks to be right on track. 

“He’s had success at this level,” Ross said. “And in a big market. I think his mindset, his mentality will be really good for that group down there. The arm, obviously, it’s electric stuff when he’s in the zone and when he’s healthy.”

The Cubs acquired Heuer from the White Sox as part of the Craig Kimbrel trade during the 2021 season. The righty fashioned a 1.52 ERA in 21 games in ’20 while averaging 97.6 mph on his fastball. In ’21, Heuer had a 4.28 ERA in 65 games between both Chicago clubs but saw his velocity fade as the season progressed.

Heuer averaged 97.3 mph in April of 2021, but that rate dropped to 94.8 mph by September. In spring of ’22, the right-hander underwent surgery and lost a full season to recovery, rehab and training.

Since starting his Minor League rehab, Heuer looks more and more like himself again. Over eight games with Triple-A Iowa, he has hovered around 97 mph with his fastball, reaching back and touching 99 mph a handful of times.

“The stuff’s there,” Ross said. “But he wants to be able to command it. I think that’s probably the next step.”

To date in his rehab outings, Heuer has allowed seven runs on seven hits with 10 strikeouts and seven walks in 7 2/3 innings. On Saturday, he went 1 1/3 scoreless with two strikeouts in his third consecutive appearance with no runs allowed.

Heuer is eligible for activation from the 60-day IL on Monday, but the Cubs can keep him on a rehab assignment for 30 days from when it started (May 6). There are avenues for extending a rehab stint, but Ross hinted Sunday that Heuer could be coming soon, if he continues to trend up with his command.

“He’s getting to the back end of his rehab,” Ross said. “I think he still feels like he’s just a tick off and wants to kind of lock in his mechanics. His strike-throwing seems to be getting better every single day. So, when he’s comfortable and his date’s up, I’m sure we’ll see him at some point soon after he feels great.”