PHILADELPHIA -- It wasn't much of a surprise that Juan Soto missed Tuesday night's series opener at Citizens Bank Park. The absence of Nelson Cruz certainly came as more of a surprise.

But it was shortstop Alcides Escobar tossing a scoreless eighth inning that was the most shocking turn of events in the Nationals' 11-0 loss to the Phillies.

While Soto was out of the starting lineup for a second straight game due to tightness in his left calf, Cruz was scratched just moments before first pitch due to a stomach-related illness. Missing two of their key contributors on offense certainly didn't help the Nationals, but it's the injuries to Washington's pitching staff that have really taken a toll.

Though the injury bug has started to creep into the starting lineup, it's run rampant through the Nationals' rotation all season. After all, injuries are one of the reasons Paolo Espino found himself making his fifth start of the season on Tuesday -- one that began with him serving up a leadoff homer to former teammate Kyle Schwarber.

Espino started the season by putting up an impressive 2.03 ERA over 20 appearances out of the bullpen. However, he was pressed into the starting rotation on June 12 -- just before the Nats placed Stephen Strasburg back on the injured list with a stress reaction of the ribs. That also came shortly after the club had optioned a struggling Joan Adon to Triple-A Rochester and designated veteran starter Aaron Sanchez for assignment.

• Nationals Injuries & Moves

Fellow starters Josh Rogers (left shoulder impingement) and Aníbal Sánchez (cervical nerve impingement) were already on the IL at that point, while Evan Lee (left flexor strain) and Jackson Tetreault (stress fracture of right scapula) have since joined them. Joe Ross is out for the season due to Tommy John surgery.

"We've endured a lot of injuries," manager Dave Martinez said. "We've just got to figure out what we can do to keep these guys healthy. ... Our training staff does a great job trying to maintain these guys. For me, it's just part of the game. You see it a lot every year."

Put it all together and the Nationals have already used 11 starting pitchers this season. Only the Tigers (14), Cubs (13) and Rays (12) have used more across the Majors.

Washington’s starters have combined to put up a 5.60 ERA -- the worst in the Majors. They're also averaging fewer than five innings per start, which was again the case on Tuesday when Escobar was called upon after five Nationals pitchers needed 178 pitches just to navigate the first seven frames.

Espino lasted just 3 2/3 innings against the Phillies while serving up four runs, including a pair of homers to Schwarber.

"Today was kind of a lopsided game. When your pitcher only goes 3 2/3 innings, things can go awry," Martinez said. "So, let's just forget about this one, come back tomorrow and try to go 1-0 tomorrow."

After giving up just two home runs in 26 2/3 innings of relief this season, Espino has allowed six in 22 frames as a starter. He also has a 9.00 ERA in his past two starts after posting a 2.57 mark in his first three.

"It's just the way pitching goes sometimes," Espino said. "Two back-to-back outings where it hasn't been going my way, but I feel OK. I feel fine. I'm still executing some good pitches, but I'm also making some mistakes. That's just how baseball goes -- it's up and down."

For the immediate future, the Nationals are hoping Josiah Gray can help right the ship on Wednesday. He had a 1.13 ERA over four June starts before starting July with a clunker on Friday against the Marlins.

Beyond that, it's unclear -- literally.

The club has yet to announce a starter for Thursday's finale in Philadelphia, which would have been Tetreault's turn before he became the latest to join the IL. Rogers and Sánchez have both started rehab assignments, but the Nationals would like to see Rogers make at least one more start in the Minors and Sánchez isn't an option after pitching Sunday for Triple-A Rochester.

One thing is certain, though: Soto and Cruz returning would at least help offset some of the pitching woes.

“We've got to get our offense going,” Martinez said. “We missed two big hitters in our lineup with Cruz and Soto, hopefully they'll be available tomorrow.”