David Robertson was ready to throw from a mound for the first time since having a ligament reconstructed in his right elbow.

Then a coronavirus outbreak hit the Phillies’ facility in Florida.

That was the middle of June. Two months later, nearly a year after he underwent Tommy John surgery, Robertson will report to the Phillies’ satellite camp in Lehigh Valley for what the veteran reliever hopes will be the final step in his return to a major-league mound later this season.

“I think I’m making a lot of progress,” Robertson said Sunday. “It’s been a very difficult rehab process going through the pandemic. I just lost some time in the middle of my rehab. It kind of stung me for a little while, but I’m catching up and I’m feeling really good.”

Although his fastball velocity topped out at 88 mph a few weeks ago and has often been in the 85-86 mph range, Robertson thinks he “could probably hit 90.” For his career, his fastball has averaged 92 mph. He has thrown bullpen sessions but hasn’t faced hitters. That will happen over the next few weeks.

Manager Joe Girardi believes Robertson might be able to join the Phillies’ bullpen at some point in September.

“I think if I could get comfortable I could pitch at the big-league level in three weeks,” Robertson said. “But that’s not a hard date.”

The Phillies signed Robertson to a two-year, $23 million contract before last season. He made seven appearances before being sidelined. A setback in his recovery led to Tommy John surgery.

If the 12- to 15-month rehabilitation isn’t challenging enough for a major-league pitcher, try doing it in the midst of a pandemic. After the Phillies’ outbreak, Robertson waited a week to find out that he and his family were negative. With the Clearwater complex shuttered, the Robertsons drove home to their farm in Alabama.

“I tried to stay as active as I could with my throwing program, but it wasn’t the same as going to the complex in Clearwater,” Robertson said. “I know I missed almost a month of time. It was pretty heartbreaking.”

Robertson returned last month to Clearwater, where he said the Phillies “opened up a bubble for me.” If not for the lost time, would he be ready to contribute to a bullpen that had combined for a worst-in-the-majors 9.13 ERA entering play Sunday?

“I was feeling really good at the time of the shutdown,” Robertson said. “I honestly think I probably would have been ready by now. That’s the way things go. Everybody has had to deal with a lot of difficult things and I’m no different.”

Extra bases

The Phillies have won 17 of their last 24 games against the Mets, including 12 of the last 15 at Citizens Bank Park. ... After the game, the Phillies optioned lefty reliever JoJo Romero to Lehigh Valley. They will make a corresponding move before Tuesday night’s game that opens a two-game series in Boston. ... The Phillies are off Monday.