With Montgomery and Nathan, is Cubs pen fully armed?

MILWAUKEE – Just in time to unleash him in the crosstown series, the Cubs plan to activate longtime White Sox nemesis Joe Nathan from the disabled list Sunday and add him to their evolving bullpen.

“It sounds like he’s ready to rock and roll,” manager Joe Maddon said of the six-time All-Star, who just completed a lengthy rehab from his second Tommy John surgery.

Nathan is 41 and hasn’t pitched in a big-league game since early last season. But the big right-hander has command; his velocity’s back up to the low 90s; and Maddon reports the breaking ball is working well.

And whether he replicates the 2.39-ERA, 30-save results against the Sox that helped make him a perennial All-Star from the American League Central, the only question that really matters, of course, is how much October-caliber pitching is left in the playoff veteran’s tank.

In fact, by the end of the four-game stretch against the Sox, the Cubs might have an especially good idea of what kind of power, and what kind of reliability, they might have for late-inning work in what has been an inconsistent bullpen.

And how much they might have to suck it up for a more aggressive, even costly, push for help at the Aug. 1 deadline.

Hard-throwing rookie Carl Edwards Jr. (1.93 ERA), who had performed well in several hot spots since his recall last month, gets his first taste of the crosstown hate-fest Monday through Thursday. So does newly acquired left-hander Mike Montgomery, who’s been compared to the Cubs’ ideal trade target, Andrew Miller, since Wednesday’s trade from Seattle.

“I do like the names. Is it enough? I think it is,” Maddon said.

It’s all contingent upon whether Montgomery can continue the 2.15-ERA level of relief pitching he produced in Seattle as stakes – and his potential responsibilities – rise. And what Nathan looks like. And whether Edwards can continue to grow and develop into a dependable high-leverage pitcher.

“He’s definitely got the stuff,” said veteran starter jason Hammel of Edwards after the rookie inherited a man on second with nobody out in a turning-point sixth Friday – then retired the heart of the Brewers lineup in order to strand him. “And he’s definitely not afraid. He weighs about 140 pounds, and he can attack a ton worth of weight.”

No matter how well they pitch, both Edwards and Nathan are on Maddon’s no-fry list, with durability issues to be managed through workload limits.

“It looks good on paper,” Maddon said of the new-look strength of a new-look pen. “But you’ve got to get them out there and play it out.”

The Cubs, meanwhile, continue to pursue more strength and more depth – looking at every potential option from more bullpen help to further strengthening an already strong lineup.

Getting Montgomery early in a four-player deal that didn’t cost any of the Cubs’ highest-ranked prospects keeps big fish in play, team president Theo Epstein said.

“The prospects we moved weren’t in any other deals that we were talking about,” Epstein said after the Montgomery trade. “We haven’t touched the prospects that we were potentially going to move in some bigger deals that didn’t come to pass and may be resurrected in the future.”

That keeps them “really viable for every opportunity that’s still out there,” said Epstein, who has been reluctant to spend heavily in prospect capital for trading deadline help historically.

When it comes to helping the bullpen, the Yankees have far and away the most desirable late-inning arms in Miller and 105-mph Aroldis Chapman. They’re also playing just well enough in recent weeks to put into doubt whether they’ll trade anyone (though reports late Saturday suggested the Yankees could be pushing a Chapman deal).

And if Montgomery, Nathan and an ascending Edwards are as good as it gets for late-season help for a middle-of-the-pack bullpen? As Maddon said, it looks good on paper.

“You just don’t know,” Maddon said.