Back in the good old days, when the summer was hot and the Phillies were on a five-week run in first place, Matt Klentak made a calculation.

"We're hopeful that we can stay out of the starting-pitcher trade market," the Phillies general manager said on July 20, 11 days before the nonwaiver trade deadline, "because if you can avoid it, that's definitely a market to avoid."

Klentak's logic was two-fold. First, he preferred not to make the prospect sacrifice for Cole Hamels, J.A. Happ, or certainly Chris Archer. But also, and equally important, he didn't want to rob Zach Eflin, Vince Velasquez or Nick Pivetta of meaningful starts in their ongoing development as major-league pitchers.

And so, the Phillies sought to improve their offense by trading for infielder Asdrubal Cabrera, catcher Wilson Ramos, and later, first baseman Justin Bour and outfielder Jose Bautista, veterans who often played at the expense of young Scott Kingery, Jorge Alfaro and J.P. Crawford. True to Klentak's word, though, they stood pat with their starting pitching.

Eflin, Velasquez and Pivetta kept taking their turns in the rotation, reaching career highs in innings pitched. But the three righthanders also struggled to varying degrees and contributed to the Phillies' free fall from playoff contention. Since Aug. 1, they have combined for a 5.09 ERA and 8.5 strikeouts and 3.2 walks per nine innings. Through the end of July, they had an aggregate 4.23 ERA, and 10.1 strikeouts and 2.8 walks per nine innings.

Spahn, Sain and pray for rain? For the Phillies, it was Nola, Arrieta and the others must get better.

"I think one of the things we can say almost unequivocally is the stuff has been pretty consistent throughout for all three," manager Gabe Kapler said of Eflin, Velasquez and Pivetta. "None of them have been like, 'Ooh, the ball is just not coming out as good.' All three of those guys have the promise and the capability of being frontline major-league starters."

Given the Phillies' myriad offseason needs in other areas, it's likely the 2019 rotation will include some combination of Eflin, Velasquez and Pivetta. It seems doubtful, however, that each of the three will reprise an every-fifth-day role alongside ace Aaron Nola and Jake Arrieta.

Velasquez, 26, has generally been the most consistent of the bunch despite a 5.28 ERA since the beginning of August that has hoisted his overall mark to 4.30. He gave up five runs in four innings last Sunday in New York, marking only the third time in 14 starts that he allowed more than three runs. Although he has completed at least six innings in only 12 of his 27 starts, he probably could've gone deeper in several of those games if Kapler hadn't lifted him for a pinch-hitter with the Phillies trailing.

"I think Vinny has been very competitive," Kapler said. "It hasn't been perfect, but I think it has been competitive."

Zach Eflin has struggled since the all-star break.
STEVEN M. FALK / Staff Photographer
Zach Eflin has struggled since the all-star break.

Finally healthy after dealing with knee problems for the last few years, Eflin picked up nearly two miles per hour on his fastball and dominated through the middle of the season with a 2.32 ERA in seven starts leading to the all-star break. Since then, he has a 6.35 ERA, including a 7.71 mark in five starts since the Phillies optioned him to triple-A on Aug. 11 to keep an extra bench player for a few days.

Eflin has repeatedly insisted that it's purely coincidental that his worst outings have come since the Phillies' roster maneuvering. Likewise, he maintains that he's healthy. He blames his nosedive on a lack of fastball command. In fact, Eflin appears to have lost so much confidence in his heater that he overused his slider last Saturday night against the Mets and gave up three costly extra-base hits in a 10-5 loss.

"Zach has struggled for a while. He has struggled to be efficient," Kapler said. "He has hit more often the middle of the zone than the edges of the zone. As Zach continues to acquire fastball command, I think that's when he begins to take off."

Every time Pivetta looks poised to launch his career to the next level, he takes a few steps back. The 25-year-old had a 3.26 ERA through his first 11 starts of the season, then a 6.70 ERA over his next 10 starts. He has been better down the stretch, posting a 4.10 ERA since the beginning of August. But he hasn't gone particularly deep in games, averaging 88 pitches but only five innings per start.

"He hasn't been at his most efficient and I think that's important to note, but I also think he's making adjustments about when to start using his fastball with authority," Kapler said. "I still think he can use his curveball a little bit more."

Others agree. Bautista faced Pivetta earlier in the season and was impressed by his breaking ball. Earlier this season, assistant pitching coach Chris Young invoked Houston Astros curveball artist Lance McCullers Jr. when discussing Pivetta. And while nobody expects Pivetta to throw his curveball 46 percent of the time, a la McCullers this season, it probably should represent more than 21 percent of his overall pitch usage.

"We're still kind of learning in that regard," Kapler said.

At least the Phillies have learned more over the last two months about the starting pitchers they have, even if the conclusion was that they didn't have enough.