The hot corner belongs to Rafael Devers

Red Sox third baseman Rafael Devers hit .311 with 32 homers and 115 RBIs last season. His OPS was .916. File/Jim Davis/Globe Staff

Sixth in a series.

An error in May of last season helped shape Red Sox third baseman Rafael Devers.

The Red Sox were leading the Chicago White Sox, 4-3, in the bottom of the ninth inning. On a 2-and-2 pitch with one out and the bases empty, the Red Sox’ Ryan Brasier spun an 86-mile-per-hour slider and induced a weak grounder from Jose Rondon.

Devers charged and attempted to field it on his glove side, but the ball popped out of his mitt and Rondon reached safely. It was just the start of May, but it was Devers’s ninth error of the year.

So first baseman Mitch Moreland phoned his former teammate, Adrian Beltre, to ask if he could help guide the young third baseman. It also served as a wake-up call and the start of a regular conversation.

“Adrian talked to Raffy, and from there on, the communication was on an every-other-week basis,” Red Sox manager Alex Cora said.

Devers’s defense improved, but there’s still a ways to go.

Offensively, though, he was dominant.

Devers hit .311 with 32 homers and 115 RBIs. He posted a .916 OPS. He had 201 hits and set franchise records for hits and extra-base hits (90) in a season before age 23. Devers’s 32 homers were also the most by a Red Sox third baseman.

The point here? He can flat-out hit and does it to all fields. If there’s a player who is untouchable in the Sox’ attempt to get under the luxury-tax threshold this offseason, it’s Devers, who isn’t arbitration eligible until 2021.

“Raffy improved so much because of the work Raffy put in, in the offseason,” assistant general manager Eddie Romero said. “He dedicated himself nutritionally and conditioning-wise. He really got himself in good shape and got himself a lot more agile.”

The Sox have their third baseman of the present and future. But, back to the defense. It’s important to note that defensive metrics can be a little misleading — particularly at Fenway. He was minus-6 in defensive runs saved, but had an ultimate zone rating of 2.7, which ranked eighth among third basemen.

To the eye test, Devers’s defensive lapses still exist. He plays deep, which he learned from the Oakland Athletics’ Matt Chapman, who’s the best defensive third baseman in baseball. But unlike Chapman, some of Devers’s pre-pitch prep steps are off. He can sometimes stay on the heels of his feet, or is too flat-footed. When the ball is hit, Devers will rush some of his movements, crashing in too hard to make a play, or because of his setup, get burned on plays going to his right.

Devers is really good when ranging to his left and can sometimes take balls away from shortstop Xander Bogaerts. Nonetheless, the work won’t stop for Devers.

“There are a few things that Adrian told him to do in the offseason and what he should do in spring training,” Cora said. “I’m looking forward for him to work that way and see where it takes him.”

The backup situation at third base isn’t that complicated. The Sox could plug in Michael Chavis or even Bobby Dalbec, who has a chance to make the team out of spring training.

“We saw Bobby toward the end of the season, those 10 days in Fenway, and we talk about making some adjustments,” Cora said. “After that, he actually went to Arizona to work out. He worked out with Dustin [Pedroia] a little bit. He did a good job.

“It’s a guy that we do believe controls the strike zone. Obviously, there are going to be swings and misses, we know that. I do believe he doesn’t chase as much as people think and he can have an impact sooner than later for us.”

Dalbec hit 27 homers in 2019 to go along with an .816 OPS in Double A and Triple A. Chavis proved himself to be a powerful bat at the major league level, hitting .254 with 18 homers in 382 plate appearances.

Like Dalbec, he is prone to swing-and-miss and strikeouts, but he would be more than a capable backup to Devers because he has big-league experience and spent four games at third in 2019. The Sox want to create as much depth as possible, and the recent acquisition of Jose Peraza serves as another option at third.

Devers played in 151 games at third, so with the exception of occasionally resting, the position is his.

Third base outlook

Primary 2019 starter: Rafael Devers

Projected 2020 starter: Devers

Major league depth: Michael Chavis, Jose Peraza

Prospects to watch: Bobby Dalbec

Around the Horn

Part 1: It’s all about the rotation if Red Sox hope to rebound in 2020

Part 2: How should Chaim Bloom approach changing the Red Sox bullpen?

Part 3: Red Sox catcher Christian Vazquez is the established starter, but who will be his backup?

Part 4: Giving Bobby Dalbec a chance to start at first base makes sense

Part 5: Starting at second base for the Red Sox? TBD

Part 6: The hot corner belongs to Rafael Devers