FORT MYERS, Fla. — Did Ceddanne Rafaela have a good rookie season?

It depends on what you watched.

The 24-year-old from Curacao was one of the best defensive players in the game, starting 71 games at shortstop and 72 in center field. He had a combined 10 defensive runs saved at two difficult positions.

But Rafaela also had a .274 on-base percentage, fourth lowest among qualified players in the majors. He struck out 151 times in 571 plate appearances and drew only 14 unintentional walks.

Rafaela walked twice from June 18 to Aug. 5. At that point of the season a pitcher could have rolled the ball to the plate and he would have taken a swing.

It was not the return the Red Sox expected when they signed Rafaela to an eight-year, $50 million extension at the start of the season.

But at his young age, Rafaela is far from a finished product. He views last season as a necessary lesson, painful as it was at times.

“I learned what it takes to play 162 games and it’s hard,” Rafaela said Saturday. “Not physically, more mentally.”

The fruitless at-bats and bad swings wore on Rafaela. That he led American League rookies with 75 RBIs offered no solace.

“I knew I had to change what I was doing and have better at-bats,” he said. “I needed a better plan.”

In December, Rafaela started hitting at a facility in Hialeah, Fla., close to his home in Miami. It’s where J.D. Martinez has trained for years.

Rafaela worked on pitch recognition, having better discipline at the plate, and getting stronger.

Red Sox coaches checked in frequently during the offseason and since spring training started, Rafaela has listened carefully to what Alex Bregman has to say.

Rafaela had a three-hit game earlier this month that included a single on a full-count slider that was off the plate. He celebrated the hit only to be told by Bregman that it was a pitch he should have taken.

“Over the course of the season if you keep swinging at that slider it’s going to be an out,” manager Alex Cora said. “So you take your walk and you move on. Having Alex around him is going to help out.”

Rafaela doesn’t have statistical goals for the season. He just knows the numbers will be better if he stops swinging at bad pitches.

“I have to think about what I don’t want to swing at as much as what I do want to swing at,” he said. “If I do that, I’ll be fine. The experience from last year is going to help me.”

Rafaela also is eager to see what can happen if he plays the entire season in center.

How good could he be?

“You tell me,” he said.

Well, the defensive metrics suggest Rafaela could be the best center fielder in the game over a full season.

“That’s my goal,” he said. “I want to get a Gold Glove. I really want to see what I can do playing center field. I’ll play wherever the team needs me. But I think I’m best in center.”

Rafaela smiled when asked if he could be as good as fellow Curacaoan Andruw Jones, who won 10 Gold Gloves.

“That’s who I watched when I was growing up,” he said. “That’s the goal. He’s a good guy for me to look at.”

Rafaela has played only center in spring training and Cora wants to leave him there.

Jones could offer an offensive model, too. He had a .317 OBP over his first two seasons and 184 games. It improved to .345 over the following six seasons as Jones became an All-Star.

For now, Cora will settle for steady improvement.

“For a first full season, it was solid,” Cora said. “But he understands there are things he needs to work on and he worked hard in the offseason.

“To be honest, you see a more mature kid. He’s stronger but the way he’s conducting himself is eye-opening.”