Joe Girardi peeked at his handwritten notes, a cheat sheet of sorts, and ran down a list of injury updates. It was mostly good news for the Phillies, progress reports on a half-dozen players who are inching closer to game action.

And then this: Vince Velasquez, the manager said the other day, tweaked a muscle in his side.

The news prompted a natural question. With less than two weeks until opening day and only four healthy starting pitchers, what would the Phillies do in the event that Zach Eflin, Spencer Howard, and Velasquez were all not ready for the season?

“Get loose,” Girardi said, chuckling.

OK, so it’s premature to consider signing a pitcher off the street — or heaven forbid, a sportswriter. Eflin and Howard, after all, tested their balky backs by throwing in the bullpen Sunday without incident; Velasquez will attempt to do so Monday. And with a day off after the season opener, the Phillies won’t need a fifth starter until April 7, the sixth game of the season, allowing extra time for the banged-up pitchers, preferably Eflin, to get ready.

The starting rotation isn’t exactly in crisis mode. Girardi’s blood pressure isn’t rising.

But the events of the past week — Eflin, Howard, and Velasquez came up with minor injuries within a three-day span, causing each to miss at least one spring-training appearance — amplified the Phillies’ biggest organizational vulnerability: a lack of rotation depth below the major-league level.

Dave Dombrowski recognized it almost immediately after taking over in December as president of baseball operations. While the Phillies prioritized re-signing J.T. Realmuto and Didi Gregorius and rebuilding the worst bullpen in baseball, they actually signed more free-agent starters to major-league contracts (Matt Moore and Chase Anderson) than relievers (Archie Bradley) because they weren’t comfortable with the volume of internal options.

“We didn’t think the organization with the young guys other than Spencer Howard — there might be some guys coming up — but we didn’t think we had a lot of depth behind the first four and then No. 5 with Howard,” Dombrowski said last month. “We don’t have that internal perspective that we felt can compete to win a division.”

» READ MORE: J.T. Realmuto scratched from Phillies' lineup Sunday

It was at once an indictment of former general manager Matt Klentak and a realization of the realities of 2021. Pitchers will be retraining their arms for the rigors of a 162-game season after last year’s unprecedented 60-game dash, and nobody knows what impact that will have. Injuries may spike. Pitching depth, always important, will be essential.

If any team could handle three pitcher injuries in one week it would be the Los Angeles Dodgers. Their rotation goes nine deep, with Walker Buehler, Trevor Bauer, Clayton Kershaw, David Price, Julio Urías, Dustin May, Tony Gonsolin, and prospects Mitch White and Edwin Uceta. But the Dodgers are more of an outlier than the norm.

The Phillies’ 40-man roster consists of 24 pitchers, at least half of whom are starters. But triple-A options Ramón Rosso and Adonis Medina have pitched a total of 13 2/3 innings in the majors, while lefty Damon Jones has not yet made his major-league debut. Bailey Falter and Francisco Morales haven’t pitched above double-A and A-ball, respectively.

During Klentak’s five-year tenure as general manager, Aaron Nola and starter-turned-reliever Adam Morgan were the only pitchers to make more than 20 starts for the club. Howard made six starts last season, while lefty Cole Irvin made three over the last two years and got sold to the Oakland Athletics in January.

The Phillies weakened their rotation depth last August in the ill-fated trade with the Red Sox for relievers Brandon Workman and Heath Hembree. Nick Pivetta, who needed a change of scenery, went to Boston, but so did Connor Seabold, a former third-round pick with back-of-the-rotation potential.

» READ MORE: Phillies starting pitchers Zach Eflin, Spencer Howard, and Vince Velasquez all struggling with injuries

It was important, then, that Moore and Anderson were solid in spring training. In taking hold of rotation spots behind Nola, Zack Wheeler, and Eflin, they effectively turned Howard and Velasquez into multi-inning relievers and/or starter insurance. It would help, too, if the Phillies could somehow talk veteran right-hander Iván Nova into beginning the season at the alternate site.

Just the same, the past week underscores Velasquez’s continued value to the organization. He’s 28, with an ERA that has risen in each of the last three seasons (4.85 to 4.91 to 5.56). With a $4 million salary, he’s also expensive for essentially a No. 6 or 7 starter.

But although the Phillies listened to trade offers for Velasquez in the offseason, his ability to slide into the rotation in case of an injury would seem to outweigh the potential return. The Phillies needed him in the rotation down the stretch last season and likely will need him at some point again this year.

If that wasn’t evident before, it should be after the last week.