ST. LOUIS — From top to bottom, Cubs rookie Matt Shaw’s home-run swing Sunday looked far different from the first home-run swing of his career a little more than four months ago.
His hands started higher. He stood up taller. His stance was more open. His leg kick was more subtle.
It was the result of months of adjustments, trial and error. And it all has led to an explosive 3½ weeks out of the All-Star break.
‘‘I think Matt’s always going to be a bit of a tinkerer mechanically,’’ manager Craig Counsell said before the Cubs’ 3-2 loss to the Cardinals. ‘‘It’s going to look different from time to time. We’ve seen enough different stances already this year that I think you’re going to see that throughout his career. But it’s all this journey of getting better.’
The Cubs’ offense had been quiet against Cardinals starter Sonny Gray until Shaw’s tying two-run homer in the fifth inning. It was his third homer in his last four games and his seventh since the All-Star break. He entered play Sunday hitting .333 with a 1.110 OPS during that span.
The Cubs, however, squandered Shaw’s blast to lose the three-game series at Busch Stadium and drop to six games behind the National League Central-leading Brewers.
‘‘We’ve talked about Matt so much this year, of what the mechanics are and this and that,’’ hitting coach Dustin Kelly said Sunday. ‘‘What I’ve seen from him the most is just the intent to hit the ball really hard. And I think a lot of that has just come with confidence and comfort. . . . It doesn’t always happen right away.’’
Shaw, whose first taste of the majors was Opening Day in Tokyo, was sent down to Triple-A Iowa for a month in mid-April. He went on a hot streak when he first returned to the Cubs, then sunk into another slump.
This most recent version of him at the plate has been the best.
‘‘What we’ve noticed the last couple of years is guys have to make these adjustments in the big leagues,’’ Kelly said. ‘‘We can do as much as we can with them in the minor leagues and put together really good [development] plans for them. But it just doesn’t happen as much until you get to the big leagues because the pitching is so different here.’’
Making swing changes while dealing with the pressure of playing in the majors for the first time is plenty to juggle.
‘‘Plus, go help the team win — that’s the hard part,’’ Counsell said. ‘‘That’s what prevents people from doing it because they know the changes are going to take time, and that means there’s probably not going to be success for a little while. And that means I’m not helping the team, and then I might not play. All that stuff is real.’’
Through all that, Shaw has committed to evolving offensively and defensively. Now his and the Cubs’ patience are paying off.
Shaw had the biggest swing of the day for the Cubs. It countered the two-run homer Cubs left-hander Shota Imanaga surrendered to Pedro Pagés in the third.
‘‘It really felt a huge part of the game,’’ Shaw said. ‘‘It’s just one of those moments that felt like we needed to get going a little bit. And so it was exciting.’’
As Shaw’s long fly landed in the Cubs’ bullpen, he balled his fists and let out a shout.
‘‘I usually am pretty even-keeled,’’ Shaw said. ‘‘I definitely let out a little bit of emotion there. But it’s unfortunate how the game ended up, for sure.’’
The Cardinals pulled ahead in the seventh. Imanaga had allowed only two hits and had retired 14 baters in a row before Jordan Walker singled with two outs, stole second and scored on a single by Nolan Gorman.
The Cubs didn’t score again, despite a walk and two singles in the ninth. A close call on a stolen-base attempt by pinch runner Jon Berti broke the Cardinals’ way for the second out before Shaw grounded into a fielder’s choice to end the game.