PHILADELPHIA — Not only did the Yankees lose three games in Tampa Bay over the weekend, they also lost Gary Sanchez for likely three to four weeks with a Grade 1 right groin strain, according to Aaron Boone.

The catcher was placed on the 10-day disabled list Monday before the Yankees faced the Phillies. Kyle Higashioka was called up from Triple-A Scranton/Wilkes-Barre to take Sanchez’s spot on the roster, but Boone said Austin Romine would do the “bulk” of the catching in Sanchez’s absence.

“It’s huge,” Boone said before the Yankees opened a three-game series at Citizens Bank Park on Monday. “When Gary Sanchez is out of your lineup, that’s a big deal.”

But not as big as it could have been, since Sanchez has not approached his expectations for much of the season.

In his last 20 games, Sanchez was just 8-for-77 with two doubles, two homers, eight walks and 23 strikeouts.

Boone acknowledged Sanchez could use the time off not just to heal physically, but mentally, as well.

“Hopefully it’s a positive not only to get him physically right, but it’s a little break mentally,” Boone said. “I know he’s been grinding, working really hard. He’s probably wearing it mentally and emotionally. He can refresh a little bit and come back and we have a dynamic player the second half of the season.”

In the meantime, the Yankees will turn to Romine, who has excelled in a backup role. He’ll now be asked to do considerably more.

“With [Romine], we’ve got to watch him since he hasn’t played every single day a lot,’’ Boone said. “I think he’s a way better hitter than he was even at this point last year mechanically. I think he has the ability to be an everyday catcher. The biggest challenge for us is going to be … being cautious not to run him into the ground. I’m confident we’re gonna get a really good performance, an every-day kind of performance.”

That will be fine in the short term, but the Yankees are relying on Sanchez to be a major force in the middle of the lineup and he has already suffered two injuries to his lower half this season, with a calf injury bothering him earlier.

Asked if there was a concern his legs might be an issue the rest of the way, Boone said, “I hope not.”

“It’s something we’ve been trying to attack as aggressively as we can over the last month, obviously while playing him every day,’’ the manager said. “Hopefully this time on the disabled list is useful in the sense that we get the groin right and it’s also a time we make sure he’s staying proactive with the conditioning so that when he does come back, he’s in the best possible place so that he can be physically sound the rest of the way.”

Aaron Judge will be among those asked to pick up the slack.

“It’s tough to lose an All-Star catcher,’’ Judge said. “We have a lot of capable people here and we can kind of move on and just keep going. We can’t really change what we do.”

They’ll also call on Higashioka, who went 0-for-18 in sporadic at-bats last season with the Yankees and comes back with just a .593 OPS in 205 plate appearances with SWB.

“I feel I’m more prepared for a backup role,’’ Higashioka said. “I’ve asked what other guys do, like [Ronald] Torreyes and Romine.”

As for his hitless streak last season, Higashioka said: “I think about it from time to time. I’m confident I’ll get that opportunity and will get it done.”