PHILADELPHIA -- The Phillies have leaned heavily lately on David Robertson.

They lost Seranthony Domínguez and Corey Knebel as late-inning relievers in mid-August because of injuries. Domínguez could rejoin the bullpen this weekend following an encouraging rehab appearance Thursday night with Triple-A Lehigh Valley. Knebel, however, is lost for the year. Robertson has been the Phillies’ go-to choice in the ninth inning ever since. Thursday, he was their only choice. José Alvarado, Connor Brogdon and Andrew Bellatti were unavailable to pitch.

“This is what you play baseball for, this is the playoff push,” Robertson said. “I felt good enough to get the job done.”

But Robertson blew the save in the ninth inning in a 6-5 loss to the Marlins at Citizens Bank Park. The loss dropped the Phillies into the third NL Wild Card spot with 25 games to play, a half-game behind San Diego. The Phils are 2 1/2 games ahead of the Brewers.

Philadelphia owns tiebreakers over both teams.

Robertson entered the ninth inning with a one-run lead and Lynyrd Skynyrd’s “Sweet Home Alabama” blaring over the ballpark’s sound system. He allowed a leadoff double to Garrett Cooper on a 1-0 cutter that caught the middle of the plate. Rhys Hoskins then committed a two-base error to allow the tying run to score. Robertson walked Avisaíl García to put runners on first and second before Brian Anderson rolled a ball through the right side of the infield to score the winning run.

“A leadoff double sucks,” Robertson said. “It’s tough to dig your way out of that one. I made some good pitches. A little bit of bad luck. It’s one game. It’s a game we should have won. I should have been better than that.”

Robertson joined the Phillies following an Aug. 2 trade with the Cubs. He had a 2.23 ERA in 36 appearances. He did not allow a run in his first seven appearances with the Phillies. He has a 6.14 ERA in his past seven appearances though, including Thursday.

Robertson’s cutter averaged 91.8 mph against the Marlins.

It averaged 93.2 mph this season.

“I don’t think we’re putting him in the danger zone, but I think he’s a little bit tired,” Phillies interim manager Rob Thomson said.

Robertson’s blown save followed a 41-pitch appearance Sunday in San Francisco. The Phillies tried to get six outs out of him, but the Giants scored twice in the ninth to sweep the series. Robertson threw 24 pitches in Tuesday’s 3-2, walk-off victory over Miami. He allowed one hit and two walks, but he worked out of the jam.

“I feel good,” Robertson said. “My velo might be down a tick. I’m not looking up at the board. It feels good coming out of my hand. I feel like it’s one of those days where I didn’t get the job done. I just didn’t make enough good pitches.”

Every loss like this stings, of course, but they sting a little more this late in the season. So much is at stake.

This one also stung because the Phillies almost beat Sandy Alcantara again.

Alcantara very well could be the NL Cy Young winner in 2022, but Philadelphia took a 5-4 lead against him in the fifth with the help of a botched play in center field by JJ Bleday. No matter. The Phillies hit Alcantara when it mattered. It would have been their fourth consecutive victory this season against him.

The Phillies had never won more than two consecutive games in a season against an eventual NL Cy Young winner. They won two consecutive games against Arizona’s Brandon Webb in 2006. They won two consecutive games against Pittsburgh’s Vern Law in 1960. The last time a team beat the eventual Cy Young winner four consecutive times in a season was 2018, when the Braves beat Mets ace Jacob deGrom in five consecutive tries.

“I don’t make lists, but if you’re making a list of the best pitchers in the game you’re talking about him,” Alec Bohm said. “You get to him, you get a lead, yeah, you want to close it out, but it didn’t happen. Move onto the next one.”

The Phillies need Domínguez back. He has been their best reliever this season. He has been one of the best relievers in baseball. He walked the first two batters he faced in Triple-A, but he recovered. He struck out one batter and did not allow a hit.

Thomson said Domínguez's fastball touched 100 mph.

“We’re going to talk to him [Friday], find out exactly where he is, how he feels confidence-wise,” Thomson said. “It sounded like it was really good.”

He would help, right?

“Yeah, but we’ve got to be careful with him, too,” Thomson said.