PHILADELPHIA -- The story of Zack Wheeler's first three starts this season was how little support he had received from his offense. Perhaps there should have been equal focus placed on the lack of defensive help.

No pitcher in the Majors has had worse defensive play behind him this season than Wheeler, according to Statcast, and the Phillies did nothing to change that in Sunday afternoon's 9-2 loss to the Pirates at Citizens Bank Park. Wheeler once again received little assistance on either side of the ball before ultimately serving up a game-changing grand slam in the sixth inning to end his day.

"It's kind of how you bounce back, what are you going to do about it?” said Trea Turner, who hit his first home run of the season in the third inning. “We've got the right group of guys. We just need to play a little bit better, and I think we will."

The decisive sixth frame started when Alec Bohm let a routine grounder roll under his glove for an error. Wheeler followed with an eight-pitch walk to Rowdy Tellez before Andrew McCutchen lofted a 68.5 mph blooper into shallow center for a base hit, setting the table for Jack Suwinski's slam.

“For the most part, he’s pitched really well,” manager Rob Thomson said. “Even in that last inning today, error, walk, fly-ball base hit and then Suwinski. … He’s pitched very well all year.”

While Bohm's misplay was the lone error behind Wheeler (Brandon Marsh added another in the eighth), that hardly tells the full story.

The Pirates' first run scored on a double steal in the fourth, when catcher J.T. Realmuto's throw sailed into center field, allowing McCutchen to coast home from third. That play unfolded not only with two outs, but with Wheeler already having two strikes against the light-hitting Michael A. Taylor.

That all came after Wheeler had already induced a pair of ground balls earlier in the frame, but the Phillies were unable to turn either into a double play. Entering Sunday, Phillies pitchers had forced 30 ground balls that were handled by an infielder in a potential double-play situation. Only seven resulted in two outs. Twenty-two produced just one out, while the other led to zero thanks to a throwing error.

Philadelphia pitchers produced four such grounders on Sunday. None resulted in two outs. There are plenty of factors -- exit velocity, runner speed, hit placement, etc. -- but that's a lot of extra outs being given away.

“It's something we went through last year at the start of the year, too,” Thomson said. “Then, as time went on, we got better at it. I know [infield coach Bobby Dickerson] is really working hard at it to clean that up.”

Overall, the Phillies have turned only seven double plays in 16 games this season. Only five teams have turned fewer, which is rather remarkable considering Philadelphia pitchers entered Sunday with the second-highest ground-ball rate in the Majors (51.5%).

“You're never going to be perfect and whatnot, but I see what Bohm does and Stott, Bryce [Harper], me, [Edmundo] Sosa -- everybody,” Turner said. “We're out there every day trying to make sure things like that don't happen, but it's the game of baseball. It's not that easy.”

While the defense did him no favors, Wheeler also once again received little run support. Along with his solo homer in the third, Turner added an RBI single in the fifth, but that was it for the Phils. In Wheeler’s four starts, they’ve scored only five runs while he has been in the game.

“It’s frustrating,” Thomson said of falling to 0-4 behind Wheeler. “We haven't really swung the bats in his starts. That'll change."

Things didn’t get any better once Wheeler exited.

Marsh let a one-out single roll under his glove in the eighth, allowing Jared Triolo to go all the way to third. Triolo scored two batters later on a Realmuto passed ball. The Phillies had five errors, four wild pitches and two passed balls over the final three games against the Pirates.

“In today's game, there were a lot of cases where we gave extra bases to people -- and you can't do that,” Thomson said. “That's not typically what we do. It was just kind of a weird game day today. We’ve just got to kind of dust [it off] and come back in here tomorrow."

Though the Phillies let their shot at a series victory slip away Sunday, they still have a prime opportunity to turn in a quality homestand. They start a three-game set against the Rockies (4-12) on Monday before welcoming the White Sox (2-13) next weekend.

"It's 162 [games] and this is just one of them,” Wheeler said. “We'll be all right."