PHILADELPHIA -- The Phillies’ front office believed it had “roughly” a top-10 rotation entering the season, but its projection has not matched the rotation’s performance.

That has put heat on first-year pitching coach Chris Young.

“Yes,” Phillies manager Gabe Kapler said Tuesday, when asked if he is satisfied with Young’s performance. “The way I’d elaborate is, we’ve seen some improvements over the course of the last six weeks. That stands out to me. We’ve also seen a guy in Jason Vargas who has come over and performed well for us. But obviously, he’s had some success in his career. I think Drew Smyly is a good indication that good work is being done. His last start was excellent, obviously. I think if you asked Drew, he’ll speak to some of the work that he’s done since he’s been here. That’s how I’d address it.”

Young was unavailable to comment before the game.

The Phillies thought they had a formidable rotation because they believed in the continued progression of right-handers Nick Pivetta, Zach Eflin and Vince Velasquez. The trio showed flashes of potential last season under former pitching coach Rick Kranitz, whom the team dismissed in the offseason. The team made the move because it believed Young, who had a scouting background before he joined the Phillies, was too valuable to lose to another organization. Kranitz was respected and popular among Phillies’ pitchers, and many were upset last fall when the team decided he would not return.

But Pivetta, Eflin and Velasquez have taken steps backward this season. Each has been demoted to the bullpen at some point. Pivetta, who many considered to have breakout potential, struggled so much that he was optioned to Triple-A twice. He remains in the bullpen, though Eflin and Velasquez rejoined the rotation.

Eflin recently returned to his roots by asking to stop throwing a high percentage of four-seam fastballs in favor of his sinker. Coincidence or not, he is 1-0 with a 2.50 ERA in his last three starts.

The Phillies’ rotation last season ranked third in the National League in FIP (3.76), fourth in xFIP (3.77), fourth in WAR (15.2), fourth in strikeout percentage (24.1) and fourth in walk percentage (7.6), according to FanGraphs. It had a 4.12 ERA, which ranked 11th. This season’s rotation is 13th in FIP (4.88), 11th in xFIP (4.60), 12th in WAR (7.2), 11th in strikeout percentage (21.2) and 10th in walk percentage (8.1). It is 11th with a 4.58 ERA.

The Phillies dismissed hitting coach John Mallee last month. Charlie Manuel took his place. While sources said Young’s job had been under discussion, he has remained.

For Seranthony, why not?

Phillies right-hander Seranthony Domínguez has not pitched since June because of a UCL injury in his right elbow. So far, he has avoided surgery. He is scheduled to throw from 90 feet Wednesday and has a bullpen session tentatively scheduled for Sept. 20.

The season finale is Sept. 29, meaning he is a tremendous long shot to pitch again this season.

“It depended how quickly we accelerated him from there,” Kapler said. “What if it comes down to the last day of the season and he’s available?”

Rehab roundup

• Roman Quinn began a running program Tuesday. He will begin a hitting program Wednesday. The Phillies hope he returns before the end of the season.

• Outfielder Jay Bruce is taking ground balls and fly balls in the outfield but remains unable to throw because of an elbow issue.

• Right-hander Edubray Ramos is scheduled to throw a live batting practice session Wednesday.

• Right-hander Juan Nicasio has a bullpen session scheduled for Thursday.

• Right-hander Pat Neshek had hamstring surgery Tuesday.