PHILADELPHIA -- Zach Eflin finished his season making a strong case to be in the Phillies’ rotation in 2020.

He probably will be.

Eflin allowed three runs in 7 2/3 innings in Saturday night's 9-3 victory over the Marlins at Citizens Bank Park. The win improved the Phillies to 81-80, guaranteeing they will have their first season without a losing record since finishing .500 in 2012. If the Phillies beat the Marlins in Sunday’s finale, they will finish with a winning record for the first time since ‘11.

• Box score

Bryce Harper, Maikel Franco and César Hernández homered to back Eflin.

“Gotta do it. Gotta go out there and win tomorrow,” Harper said. “That's huge for us. We can go 82-80. Of course, that's not where we want to be, but winning seasons are good. It's a stepping-stone into next year.”

Eflin took some positive steps in 2019, going into the winter with reasons to be optimistic about the future. He went 10-13 with a 4.13 ERA, but he showed flashes of his potential at the beginning and end of the season. He was 6-7 with a 2.83 ERA through his first 14 starts before going 1-4 with an 8.75 ERA in his next 11 appearances, including four relief outings following a demotion to the bullpen in July.

The 25-year-old right-hander grew tired at times of throwing four-seam fastballs at the top of the strike zone, putting his favored sinker in his back pocket. Eflin got back to his sinker once he rejoined the rotation in August because he wanted ground balls and quick outs. It worked. He compiled a 3-2 record with a 2.83 ERA in his final seven starts.

Eflin's overall performance the past two seasons -- he is 21-21 with a 4.23 ERA in 56 appearances (52 starts) -- has put him ahead of righties Vince Velasquez (16-20, 4.88 ERA in 64 appearances/53 starts) and Nick Pivetta (11-20, 4.99 ERA in 63 appearances/45 starts) on the depth chart.

“I think there’s a fairly clear distinction, and that’s not meant to be a knock on Vinny or on Nick,” Phillies manager Gabe Kapler said. “I just think that Eflin has experienced more sustained success. I also think he’s been dominant for longer stretches of time, and the net of the two seasons, the numbers combined look like an established Major League starter’s. There’s probably less to poke holes in. Again, this is much more about Eflin and the success that he’s having than the lack of success that maybe Nick has had or some of the struggles that Vince has experienced. I personally think that Eflin has really established himself as a dependable piece of a Major League rotation.”

Eflin’s line score Saturday would have been even better, but Neil Walker hit a high pop fly that kept carrying until it landed a couple rows into the right-field seats for a two-run homer with two outs in the eighth inning.

Home run or not, Eflin figures to join Aaron Nola and Jake Arrieta in the 2020 rotation. How the rest shakes out remains to be seen. But Eflin and Kapler seem to agree on what Eflin needs to do to make sure he is more consistent next season.

“Body armor,” Kapler said. “More just about physical durability. Zach is a strong, athletic guy. He can be even more strong and more athletic.”

Added Eflin: “I think the most important thing would be to get on a pretty good workout routine and really kind of try to make some gains this year. Maybe increase my weight a little bit, lose a little body fat and be more conditioned going into Spring Training. Not that it affected me at all this year, but just getting on top of that. I’ll start throwing in December. I won’t change too much with what I did last offseason because I was pretty healthy the whole season. But really, just staying locked in in the offseason and really just gearing up for 2020 and making sure I come to spring with all five pitches and I’m ready to go.”