Baseball is a game of adjustments, especially if you’re a rookie.

From facing big-league curveballs to cross-country road trips, there is plenty that is new this season for Rockies first baseman TJ Rumfield. However, in his first 39 games, Rumfield showed those adjustments are being taken in stride.

Through those first 39 games entering Saturday’s contest at Philadelphia, Rumfield ranked high among all qualified MLB rookies, including tying for first in games played (39) while placing second in hits (39), fifth in RBIs (21) and fourth in batting average (.271).

Additionally, those 39 hits lead all Rockies, and he is tied with Troy Johnston for the most multi-hit games by a Colorado batter with 10.

He’s also answered the question of who could be a potential long-term solution at first base in Denver after the plug was pulled on the Michael Toglia experience this offseason.

Rumfield, who turns 26 on May 17, made his presence felt in spring training, leading the Rockies with five home runs and tying for the team lead with 13 RBIs. Rumfield not only won the Abby Greer Award, given annually to Colorado’s spring MVP, but also a spot on the Opening Day roster.

“It’s one thing to do it (in) spring training. It’s another thing to do it during the season and it’s been impressive,” Rockies manager Warren Schaeffer said. “Clearly, there’s a plan. When you have a plan and stick to the plan, that just shows you have a slow heartbeat.”

The phrase “a slow heartbeat” is often baseball code for not panicking or making rash decisions during a game. For Rumfield, however, leaning into that terminology is about knowing his strengths and finding ways to make them even stronger.

Rumfield’s strikeout rate through Friday’s win in Philadelphia was at 15.7%, well below the MLB average of 22.1%. The ability to put the ball in play fits in with Colorado’s philosophy of lowering strikeouts after last season’s 1,531 whiffs, the third-most strikeouts in franchise history.

“It’s how I was raised,” Rumfield said of his ability to put the ball into play. “Playing pepper in the backyard or playing Wiffle ball, you’re going to try to hit everything. It’s tough to do that at this level, but it’s about wanting to hit it where it’s pitched and react. That’s what this game is all about is being able to react.

“I’ve always taken pride in being able to put the ball into play.”

Putting the ball in play, however, means you’re constantly adjusting to the MLB pitchers who are already adjusting to you. It’s a continuous chess match, and Rumfield’s latest move is already paying off.

Last Sunday at Coors Field, Rumfield faced Atlanta Braves pitcher Spencer Strider, who was making his season debut after battling through an oblique injury. It was also the same day Rumfield decided to, as he described it, “tone down” a leg kick that has been a noticeable part of his swing since his arrival with the Rockies.

“I was trying to just be ready to hit instead of getting beat with a pretty big move that I came into the league with,” Rumfield said. “It’s the way I’ve played my entire life, but this is obviously a level that requires a lot more than the past. It requires adjustments, so I was lowering that leg kick and trying to be ready for everything.”

The adjustment has worked this past week for Rumfield. He’s hit a pair of home runs during that span (part of the five he has on the season), including a solo shot against Strider.

“It usually doesn’t happen that fast, but it happened that day,” Rumfield said of the payoff from adjusting his swing mechanics. “I was like, ‘OK, this is something I can work with and continue to tinker with.’ Ever since then, it’s been just trying to tone it (leg kick) down and just be ready to go.”

Rumfield’s arrival in Denver didn’t come with great fanfare or high expectations. However, looking back, it’s clear the move could be one of the most significant for the Rockies this season.

Brought to the Rockies in a trade with the New York Yankees for reliever Angel Chivilli, Rumfield was announced as a new member of the roster on the same day Colorado made a deal with the Minnesota Twins for infielder Edouard Julien and reliever Pierson Ohl.

With Toglia no longer in the mix for Colorado at first base, Julien was seen as someone who could make an immediate impact. Meanwhile, Rumfield, who had never played in a major league game after being selected by the Philadelphia Phillies in the 12th round of the 2021 MLB draft, was seen by many as more of a depth piece who might be able to make an impact for the Rockies in the future.

That view has changed dramatically, thanks to what Rumfield showed in spring training and early in the season.

“Everything we saw in spring training, he’s been taking it right into games this season,” Schaeffer said. “Spring training stats are empty, but it’s the things within them that matter. The ability to take walks, the ability to fire at balls in the zone.

“We’re a big chase team. We have been historically for the last couple of years, so a guy like that stands out in terms of his skill set.”