PITTSBURGH — Aaron Nola was supposed to emerge as the Philadelphia Phillies' ace this season.

After a promising beginning, he's struggled of late, including on Saturday when he was tagged for six runs and six hits in four-plus innings while the Phillies lost to the Pittsburgh Pirates 7-4.

"When he's at his best, he has control of all his pitches," Phillies manager Pete Mackanin said. "He's lost his control and he needs to a find a way to get it back."

Nola (5-9) impressed as a rookie last season, going 6-2 with a 3.59 ERA in 13 starts, and then went 5-4 with a 2.65 ERA in his first 12 starts this season.

It's unraveled since. Nola took a step backward from his last start when he pitched six shutout innings against the Miami Marlins on the heels of giving up 30 combined runs in his previous five outings.

The Pirates drove him from the game during a five-run rally in the fifth inning that included two-run singles by Gregory Polanco and David Freese.

Polanco's hit put the Pirates ahead 4-3 and chased Nola. Freese's hit off Severino Gonzalez pushed the lead to three runs, and Francisco Cervelli capped the inning with a sacrifice fly to help Pittsburgh win for the fourth time in six games.

"I didn't have control of my curveball from the start and I just kept falling behind in the count, felt like I was 1-0 on everybody," Nola said. "I still thought I did OK until the fifth inning. I left a couple of balls up and over the plate and they made me pay with some big hits."

The Pirates' Tyler Glasnow exited his second major league start in the fourth. The rookie right-hander was recalled from Triple-A Indianapolis earlier in the day and allowed two runs (one earned) and four hits in three-plus innings. The 6-foot-8 22-year-old is one of the best pitching prospects in baseball.

Manager Clint Hurdle said he had "no sense at all" of the severity of the injury, but Glasnow did not seem overly concerned.

"It's a long year and you're always going to have things come up," Glasnow said. "It was kind of a progression, I guess, inning by inning got a little worse and they felt like it was time for me to come out."

Glasnow also hit two batters, including catcher Cameron Rupp, who left the game in the third inning after being struck in the left ear flap of his helmet. Rupp did not display any concussion symptoms but will be re-examined Sunday as part of Major League Baseball's protocol for head injuries.

Odubel Herrera had his second straight three-hit game for the Phillies after going 4 for 41 in his previous 11 games.

"It was getting pretty ugly for about a week there, so it feels good to get some hits," he said.

Cesar Hernandez hit a pair of RBI singles and was one of four Phillies with two hits along with Andres Blanco, Tommy Joseph and Carlos Ruiz, who took over behind the plate for Rupp. Blanco and Joseph hit run-scoring singles.

Cervelli went 2 for 3 and was the only Pirates player with multiple hits — the Phillies outhit Pittsburgh 12-8. Starling Marte and Jordy Mercer also drove in runs.

Juan Nicasio (8-6) allowed one run in two innings in relief of Glasnow. When Glasnow left, the score was tied 2-2 and the Phillies had runners on first and second with none out, but Nicasio escaped the jam unscathed.

Mark Melancon closed with a scoreless inning for his 29th save.

TRAINER'S ROOM

Phillies: 3B Maikel Franco (sore left wrist) sat out after being hit by a pitch in the first inning of Friday night's 4-0 win. Franco is considered day-to-day.

Pirates: RHP Ryan Vogelsong (facial fractures) played catch before the game after leaving his rehab start Wednesday with Indianapolis after four innings because of a stiff neck.

ROSTER MOVES

In addition to Glasnow, C Elias Diaz was recalled from Indianapolis while RHP AJ Schugel was optioned to the same club. C Eric Fryer was placed on the paternity list after his wife gave birth to twins — a boy and a girl — on Saturday.

UP NEXT

Phillies: RHP Vince Velasquez (8-2, 3.15 ERA) will start Sunday in the finale of the three-game series. He is 3-0 with a 2.20 ERA in six starts since his last loss May 29.

Pirates: RHP Jameson Taillon (2-1, 3.44) has allowed one run in six innings in each of his last two starts.