BOSTON – Justin Masterson lasted only five innings but it was a cause for celebration, the way this Boston Red Sox rotation is going early in the season.

Masterson needed 93 pitches. Not economic but effective.

And Boston needs effective starting pitching.

Heading into Monday’s 7-1 win over the Baltimore Orioles, Boston’s starting pitchers had a 6.24 ERA. Out of 30 major league teams, guess where that ranked?

No. 30.

So far, Boston’s offense and bullpen have overcome its inconsistent starting pitching.

Manager John Farrell knows that will carry his team only so far.

“To keep a bullpen successful, healthy and strong requires an equally strong rotation,” he said. “We’re trying to find that balance.”

Meanwhile, Boston’s starters are trying to find their spots. They have walked 27 batters (third-worst in the American League), while also falling behind and throwing in batters’ counts.

“I see good stuff,” Farrell said of his starters. “I see, at times, pitching away from their good stuff.”

In other words, they need to get ahead of hitters and keep attacking.

“If we try to simplify things with first-pitch strikes, or 1-1 strikes, then we can look to exploit a hitter’s weakness at that point,” Farrell said.

Instead, the manager said his pitchers are “trying to force the issue with so many different pitches in a given at-bat. We need to trust our stuff as starting pitchers a little bit more.”

Of 81 American League starting pitchers this young season, only one Red Sox pitcher is in the upper half when it comes to walk/hits per inning (WHIP), according to MLB statistics through Sunday.

Joe Kelly has a 0.71 WHIP, fifth-best in the league.

The other Boston WHIPs were Rick Porcello (1.47/ranked 46th), Masterson (1.50/47th), Clay Buchholz (1.65/58th) and Wade Miley (1.83/62nd).

The starters are often pitching out of the stretch.

Not surprisingly, Kelly is the only Boston starter with a respectable ERA (2.13).

Masterson has the next-best ERA at 5.74.

“To start the season, we’re all feeling decent and we started decently,” Masterson said. “Then there was a letdown.

“There are going to be some hiccups. We all know what we need to do.”

On Masterson’s to-do list was command: keeping his fastball down and throwing his slider for strikes.

“He was pretty sharp. There was progress – absolutely,” said catcher Ryan Hanigan, who has been learning this staff since spring training.

“We’re going to make adjustments.”

Hanigan expects Masterson to be able to go longer in games. The combination of the raw weather and pitch count stopped Masterson after five innings Monday. And while he had three walks, two of them were a case of pitching carefully to Baltimore’s big bats – Adam Jones and Chris Davis.

“Was smart with some pitches,” said Masterson, who knows Monday’s result could have been better.

“People will say, ‘Decent outing but only five innings.’ There will always be scrutiny. But we’ll be OK.”

The lack of an ace created angst for Sox fans in the offseason. That became especially clear when Jon Lester signed with the Chicago Cubs and the Red Sox did not trade for a big name, such as Cole Hamels.

So far, Lester is 0-2 (6.89 ERA) with the Cubs, and Hamels is 1-2 (5.00) with the Philadelphia Phillies.

A big name may not be the answer for Boston. Consistency would do wonders, however.

Masterson threw well Monday.

When it comes to this up-and-down rotation, is that a tease or trend?

“We’re going out understanding who we are,” Masterson said. “You’re starting to see it come together.”