– Joe Mauer stepped into the batter’s box this week to take his first swings of spring training, and he immediately noticed a difference.

His plan was to serve balls up the middle, and he executed that plan. But the line drives were coming easier than in recent springs. He noticed that his bat speed was a little quicker that it has been, and he wanted to do more.

“It’s kind of like, ‘Slow down, take it easy, and just ease into it,’ ” he said. “But I am excited. I feel really good, and I’m trying to slow myself down and not try to do everything right away.”

Hold the presses. Mauer is excited.

It’s a result largely of the offseason work Mauer put in with St. Paul stretching guru Roger Erickson. And it’s a potentially positive development for a Twins offense that could be pretty productive in 2015 if St. Paul’s own can approach the form that has made him a three-time batting champion.

The Twins finished seventh in the majors in runs scored — producing more runs than six playoff teams. Yes, that underscores the importance of pitching and defense, but that’s another story for another day.

The output came during Mauer’s worst season as major leaguer. He batted just .277 with four home runs and 55 RBI. He missed 34 games because of an oblique muscle strain. His first full season of playing exclusively first base was a bust, as his .371 slugging percentage ranked 22nd among first basemen. Not only did the Twins have some of the worst first base production in the league last season, they also were near the bottom in production by a No. 3 hitter, where Mauer batted most of the season.

So Mauer’s excitement over his physical state is a potential boost to a team optimistic about its ability to score runs. There are developing players in Danny Santana, Kennys Vargas and Oswaldo Arcia, a combo power-speed player in Brian Dozier, an improving run producer in Trevor Plouffe and a returning Torii Hunter.

“It’s early, but I think we’re going to be pleasantly surprised at how he looks this spring,” said Plouffe, who hit with Mauer on Friday. “That’s just my opinion.”

Knee affected power

At least all the pieces look promising on paper. Twins manager Paul Molitor was a little more cautious, given how his young players need to continue to develop.

“We had guys step up and have nice years,” he said. “And then we had guys come up and give us jump-starts like Santana and Vargas. The reality is that it was a different-looking team there at the end. We want to see that trend continue.

“We don’t have guys with long enough track records to start banking on numbers. Your question with Joe is that he’s had better years and it’s nice to think that with the trend we saw unfold last year to have a guy that is going to increase that production, potentially, because of his longer track record.”

Mauer has battled left knee problems over the past two seasons, which has made it difficult for him to drive the ball. He would compensate for the knee, and then his right hip would bother him. Sometimes he just relied on his hand-eye coordination to hit rather than use his legs. Twins hitting coach Tom Brunansky started working with Mauer this week to get his legs in sync with his swing again.

“We are going to readdress where he is going to generate a lot of his power,” Brunansky said. “Now it’s to reacquaint him with his lower half.”

Leads to follow

Mauer, 31, is aware that Molitor was more productive during the second half of his career (he had more than 1,900 hits after turning 31) than the first half. He also hasn’t ignored how Hunter has aged gracefully, batting .313 at age 36 and .304 at age 37.

As he approaches the backside of his career, Mauer is seeking similar 30-something productivity. Finally having an offseason to focus on conditioning instead of recovering from an injury or ailment, he feels, puts him on that path. Leaning on Molitor and Hunter is another way.

“Paul is one of the smartest people I’ve ever been around,” Mauer said. “I’m always trying to get better, and he’s definitely a guy you can learn from. And in bringing Torii back you have a guy who has been able to produce well into his career. As a player, you want to try things to get better, and that’s why those guys are here.”

There’s the standard spring optimism around camp that the Twins can end their run of 90-loss seasons. One reason is an offense that has the potential to be one of the best in the league, and that is fueled by Mauer telling everyone how good he feels.

He normally uses the early part of camp to just softly serve batting practice pitches into the outfield. Spraying the ball around the fields this week is tempting him to do more.

“Young Joe would have went out there and tried to put some charges in some balls,” he said.

Then, after a pause, he added: “That last round I did put a couple out. I couldn’t help myself.’’