CHICAGO -- What the Cubs’ Mike Montgomery has done twice this season used to be so commonplace that its occurrence would have barely merited a mention in a game story. But by 2017 standards, Montgomery’s feat -- earning a 10-out save -- is kind of headline news.

Montgomery piggy-backed Monday’s starter, Eddie Butler, coming on with two outs in the sixth to face the Miami Marlins' Christian Yelich. The Cubs led 3-1, but with Giancarlo Stanton standing on second base, Yelich represented the tying run. Montgomery got him on a grounder, then kept on getting Marlins out until that 3-1 score became the final tally.

“That was the whole plan,” Cubs manager Joe Maddon said of Montgomery’s outing. “We had a limited bullpen, and this is a good lineup for him.”

The win, the Cubs’ fourth straight after six straight losses on the road, moved Chicago back into first place in the NL Central, percentage points ahead of Milwaukee. And now that this superlong-save thing has happened twice, it suggests that Maddon keeps finding new ways to use the big lefty they call "Monty," who will forever remain in the warm graces of Cubs fans because it was he who was on the mound when the Cubs clinched Game 7 in the 2016 World Series.

Monday’s performance was a whole different kind of clutch from last November, but Montgomery’s 10-out save was a lifesaver for a tired Cubs bullpen after a weekend sweep of the St. Louis Cardinals. Chicago also was short a high-leverage arm because closer Wade Davis was with his wife at an area hospital for the birth of their son (baby and mother are doing well, by the way, according to a text Davis sent Montgomery after the game). The crazy thing about that long, long save was that it wasn’t even Montgomery’s longest of the season. He got the final 12 outs in a 5-1 win over the Giants on May 25.

“I like the piggyback, but the lineups [against the Giants and Marlins] were perfect,” Maddon said. “The thing about Mike, if you look at his overall breakdown numbers, he’s actually really good against righties. I’ve talked about it before, the biggest problem is the walks. He didn’t walk anybody. That’s the difference in that game, why it was so clean.”

Again, this used to be par for the course in baseball. You’d use a starter until he was gassed and in trouble, then you’d bring in your fireman to finish things off. That switch might happen in the eighth or ninth inning, or it might happen in the sixth. According to baseball-reference.com, Gene Garber had 20 saves of at least 10 outs over his career, one more than Rollie Fingers. Bob Stanley, Clay Carroll, Sparky Lyle and Hoyt Wilhelm all had 15 or more. Those guys were firemen.

Lots of things have changed in baseball over the years, but perhaps none more than the hyper-specialization of the relief pitcher. And that’s what makes the fact that Montgomery already has two saves of at least 10 outs so notable. You see, no one has had two such games in a season since Alfredo Aceves in 2011. No one has had more than two since Derek Lowe in 1999. In fact, Montgomery became just the ninth pitcher to notch at least two 10-out saves since 2000.

“You don’t see too many of those,” Montgomery said. “It worked, so we went back to it this time and it worked out again. I knew I was going to be going multiple innings. I didn’t know I was going to finish the game.”

Montgomery entered the day with 13 relief appearances in which he’s gotten at least four outs, one shy of the big league lead held jointly by the Angels’ Yusmeiro Petit and the Dodgers’ Ross Stripling. With 14 of those now under his belt, Montgomery’s ERA in those long outings dropped to 1.35.

“That’s one of the things I let them know from last year and in spring training this year,” Montgomery said. “I want to do any role that they want me to do. I’m going to physically prepare and mentally prepare for that. I just try to keep it going. Whatever I can do to help the team.”

Montgomery might be happy to fill any role for the Cubs, but he’s filling a role that had gone all but extinct. And with these recent outings of epic relief length, you have to wonder what it means in the Cubs’ search to fill the back end of their rotation. Montgomery has long thought to be one of the better in-house options to not just take the fifth spot if needed, but also to step in as a sixth starter later in the season.

Maddon alluded to those exact thoughts before Monday’s game. However, if Montgomery can string together more of these kinds of throwback saves, he might be too valuable in that role to use as a starter, even if the length of those outings means his pitch count is being stretched out to starter-like levels.

“I knew I was going to be getting in there today, and Eddie did a great job,” Montgomery said. “He shut them down for five and two-thirds. And I was ready from the get-go today.”

Butler’s outing was three things. It was his best since his Cubs debut in St. Louis on May 12. It was encouraging. And it was unconvincing.

Not until Butler strings together, at the very least, consecutive productive outings can Maddon start to look at him as a reliable option. Look at Butler’s pattern by Game Score, for which 50 is average: 70, 43, 54, 27, 62.

It’s been an every-other-game proposition for him, not too surprising for a guy with big stuff but command that comes and goes.

That’s exactly why having someone like Montgomery waiting in the left-field bullpen is such a valuable thing for the Cubs’ staff. Is he too valuable to mess with as the club cycles through rotation options?

That’s tough to say, but at the very least, Montgomery gives Maddon those options in the first place, which is a nice problem to have.