BOSTON — When the Boston Red Sox broke spring training, their plan at catcher was simple.

Christian Vazquez was to be the primary catcher, with Sandy Leon backing him up. They gave Blake Swihart a first baseman’s mitt and an outfielder’s glove. Figure it out, kid, and be ready whenever your number’s called.

As the season wore on, Leon slowly began to usurp Vazquez as the starter. Leon jumped from seven starts in April to 13 in May. When Vazquez went down with a broken pinkie finger in July, Blake Swihart – the best hitter of the bunch – found his way into Alex Cora’s trust tree.

Vazquez, who is signed through the 2021 season, guaranteeing him at least $13 million, is now nearing a return. He made rehab starts in the minors – including Monday at Hadlock Field – earlier this week, and could rejoin the team this weekend in Chicago. But the incumbent’s role is uncertain.

“Honestly, I’m very comfortable with the way Sandy is playing and the way Blake is playing,” said Cora, the Red Sox manager. “It’s always tough to play three catchers in a weekly basis at the big league level, but at the same time, we know the impact (Vazquez) can have. We’ll play it day-by-day, honestly, when he comes back.

As the Sox have run out to the best record in baseball, it’s Leon who’s backstopped them the lion’s share of the time. He’s one of the game’s elite receivers, and Red Sox starters don’t mince words about how much they love throwing to Leon.

“No disrespect to any other catcher that I’ve thrown to, but he’s the best catcher I’ve ever thrown to,” Rick Porcello said. “His game calling, he’s prepared for every pitcher, starter or bullpen. He’s kind of the heartbeat of our pitching staff. We rely on him a lot and he’s always on point, always knows what pitches to throw. Gives guys different looks. He’s as good as it gets as a game-caller and a catcher.”

The Sox have a solid system going, where Leon catches the three thoroughbreds – Chris Sale, David Price and Porcello – while Swihart snags the second-tier starters.

In doing this, Cora is putting his best game-caller with his best pitchers, and using his biggest bat for games that are bound to be higher scoring. Since Vazquez has gone down, Swihart was hitting .278 with a .742 OPS.

Meanwhile, Price is on the best run of his Red Sox career, throwing to Leon.

“He puts in the work, he puts in the time,” Price said. “He now has enough time, I feel like, in the American League to know all these hitters. You know he thinks back there. He doesn’t take his at-bats out to the field. He does a really good job.”

In eight starts with Leon behind the plate, Price’s ERA is a sparkling 1.58. With Vazquez, that rises to 4.68.

“I’ll sit down with the three of them. They understand that it’s a little bit different than it was early in the season, because Blake not only is swinging the bat well but he’s playing good defense,” Cora said. “So when the time comes, we’ll sit down, we’ll talk to them, and we go from there.”