PHILADELPHIA -- Exactly one week after turning in one of his best outings of the season -- and only three days before the Trade Deadline -- Braves right-hander Kevin Gausman was done in by three big swings in a 9-4 loss to the Phillies on Sunday at Citizens Bank Park.

Gausman served up a first-pitch homer to Bryce Harper in the opening frame, then allowed another solo shot to Phillies outfielder Adam Haseley on a 3-2 pitch in the third. The big blow, however, came on a fifth-inning grand slam by J.T. Realmuto.

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After escaping a bases-loaded, one-out jam in the third, the veteran righty loaded the bases again in the fifth -- this time with nobody out for the heart of the Phillies' order. Gausman struck out Harper on three pitches, then got Rhys Hoskins to pop out on a 3-0 pitch. He again fell behind 3-0 to Realmuto, but he worked the count full before the Phillies catcher lined a 96 mph fastball -- one that was inside and off the plate -- into the left-field seats.

"He just wasn’t hitting spots with his fastball like he did the other day," manager Brian Snitker said of Gausman's previous outing, in which he allowed one run over seven innings. "He kind of escaped the one bases-loaded [jam], and we’re a strike away from getting out of the second one. I just think the fastball command wasn’t quite as sharp as it was the other day."

That impressive start against the Nationals came after Gausman spent six weeks on the injured list with right plantar fasciitis. He said he used that time to bring back his curveball and develop a cutter, though he's seldom thrown either pitch in these first two outings.

"I threw a couple today, didn’t have any success on them," Gausman said. "Threw them for balls, but threw a couple good cutters. The thing today was I just couldn’t get out of that fifth inning."

It's no secret that the Braves have been pursuing possible pitching upgrades to both the rotation and the bullpen ahead of Wednesday’s 4 p.m. ET Trade Deadline. While the club intends to make every effort to add a reliever, the plan for the rotation figured to be influenced by the performances of Gausman and Max Fried this weekend in Philadelphia.

Fried cruised through five innings in Saturday's victory before hitting a wall in the sixth. That one rocky frame led to a final line of five runs (four earned) off seven hits and three walks over 5 1/3 innings.

Gausman, meanwhile, allowed three homers in a game for the first time this season in his final start before the Deadline. Going back to before his injury, Gausman has allowed six homers over his last four starts after serving up only five in his first 11 outings this season.

Homers aside, Gausman has a 10.13 ERA in his last five starts, dating back to May 29. Opponents are hitting .386 against him during that span, and he's allowed at least six runs in three of those five outings.

"I was able to kind of get out of some jams earlier," Gausman said. "Pitched my way into them and had to pitch my way out, but really just left one pitch [to Realmuto] -- ended up being a good spot, but maybe not in that situation."

Strangely enough, it was this time last year that the Braves acquired Gausman to provide a boost to the 2018 rotation. He certainly delivered, posting a 2.87 ERA in 10 starts down the stretch. It's been a different story in '19, however, as Gausman's latest outing raised his ERA to 5.97.

It was with those struggles in mind that Gausman spent some extra time during his rehab working on those new pitches with director of player development Dom Chiti and director of pitching Dave Wallace. He wanted to expand his repertoire, instead of solely relying on his four-seam fastball and sinker.

While the Braves were hoping his encouraging start in his return from the IL last Sunday was a sign of things to come, his latest outing against the Phillies instead left more questions about Gausman's approach moving forward.

"I just haven’t really gotten into any situations where I felt like it was really gonna help us," Gausman said of his revamped arsenal. "The times I did throw it, they just weren’t good. Those breaking balls, just didn’t execute them today, but I’m not going to stop throwing them."