FORT MYERS, Fla. — Sure, J.D. Martinez has come to the rescue of the Boston Red Sox offense.

But don’t overlook their Good Samaritan offensive spark plug from last year, Eduardo Nunez.

The fact that Nunez’s right knee withstood his Grapefruit League debut in the field and at the plate Thursday marked perhaps the most under-the-radar positive development of this already mostly cheerful and upbeat Red Sox spring training.

The lasting image, unfortunately, of Nunez’s 2017 half-season with the Red Sox was etched on Oct. 5: Nunez, in agony, being carried off the field by Manager John Farrell and a trainer after he had crumbled in a heap attempting to run to first base after a weak groundout, the second at-bat of Game 1 of the Division Series in Houston.

The loss of Nunez wasn’t the reason for Boston’s loss in that first game and then their ouster in four games to the superior Astros. Shockingly sub-standard starting pitching played a major role as well, but no Nunez meant only bad news – for the Red Sox, at least.

“It was an explosive offense with him from Pitch 1, he was a different dynamic – he brought energy, he was dangerous at the plate and the baserunning part of it, he was a factor,” said Manager Alex Cora, looking back to when his Astros had to think about how to pitch against the Red Sox.

They knew Nunez was not the same after hurting his knee in early September and then re-aggravating it two weeks later. Perhaps he was OK for the playoffs, the Astros wondered.

They worried, too.

“We had to prepare for two different teams, in a sense – one with Eduardo, one without him,” said Cora. “I was watching videos, and whatever happened – I don’t like talking about it anymore but with Eduardo, it was very different, it was a different approach, as far as like, he was aggressive from Pitch 1, there were no ‘get me over fastballs and get ahead.’ You had to be ready from Pitch 1, and that makes a difference.

“He was hitting the ball out of the ballpark – he’s a dynamic player. He’s a different guy and he made that lineup a lot different.”

In Nunez’s 38 games between July 28 and the end of the season, the Red Sox scored an average of 5.03 runs a game, a good-sized bump from their 4.79 runs a game without him.

And with him in the lineup, their record was 23-15.

Because of those numbers, re-signing him was important.

With second baseman Dustin Pedroia unable to start the regular season because of his own knee issues, having Nunez here and healthy means the Red Sox might not have to worry about an offensive drop-off at second base.

“Some swings, I expected the knee to bother me but it hasn’t bothered me yet – that’s good,” said Nunez, who went 0 for 2 against Tampa Bay’s Chris Archer on Thursday, flying out to center field and striking out on a 3-2 slider.

When asked how his at-bats felt, Nunez cracked himself up by saying, “Too hard!”

Overall, he was very pleased, and believes he has plenty of time to get the 30 or so at-bats he needs to feel comfortable at the plate.

Cora, who keeps praising Nunez’s aggressive approach at the plate, smiled about the strikeout.

“Actually, he got to 3-2, so you don’t see that often with him, he’s very aggressive,” said Cora. “Good day for him.”

Nunez is a 30-year-old, eight-season veteran who’s battled plenty of injuries in his career, but could be blossoming into a real offensive threat. Cora is giving him time and latitude to strengthen his knee and hone his offensive skills.

Like Martinez, said Cora, Nunez “has his own program … he’ll play and then he puts a batting machine on the back field and he puts the velocity up and he gets his timing down.”

Asked about Martinez, Nunez said, “We can’t wait to start Opening Day because we know how special J.D. Martinez is and how he can produce. That’s all we need.”

He’s almost right.

The Red Sox need Nunez, too.

His return and Martinez’s arrival make their lineup tougher than ever.