Mets' Travis d'Arnaud, center, is high-fived by teammates after hitting...

Mets' Travis d'Arnaud, center, is high-fived by teammates after hitting a two-run home run to score Chris Young, rear, in the second inning of an exhibition spring training baseball game against the Miami Marlins, Saturday, March 22, 2014, in Jupiter, Fla. Credit: AP / David Goldman

Travis d'Arnaud could not afford to forget.

So earlier in camp, after conversations with Mike Piazza and Yadier Molina, d'Arnaud reached for his iPhone, opened the notes app and typed in every word he could remember. On long bus rides and in quiet moments in the clubhouse, d'Arnaud often has referred to those notes.

There has been no questioning his eagerness to learn. But putting those lessons into practice has proved difficult for the Mets' catcher, who homered in Saturday's 10-2 win over the Marlins. Perhaps the home run is a sign of a breakthrough in what has been a rough camp.

"Hopefully, it does get him to relax a little bit," manager Terry Collins said.

The Mets traded for d'Arnaud in 2012 because he profiled as an offensive-minded catcher. If the Mets hope to reach at least 90 wins -- a goal that Collins mentioned again Saturday -- d'Arnaud must make the transition from touted prospect to established major-leaguer.

But after a fractured left foot forced him to miss much of last season, d'Arnaud hit just .202 after his August call-up. Those struggles spilled into this spring training, as he entered play Saturday hitting just .125.

D'Arnaud was hitless in his previous 21 at-bats before bashing the homer against the Marlins' Brad Hand.

"It was all just my approach," said d'Arnaud, who for the first time will begin the season as a big-league starter. "Maybe this spring, I didn't have an approach."

D'Arnaud has grappled with a physical flaw in his swing. For much of camp, he has fought the tendency to dip his shoulders, a subconscious move to help get more balls in the air. It also is a classic sign of overswinging. Predictably, trying to hit the ball hard produced only the opposite effect.

Instead of driving the ball with authority, d'Arnaud looked tentative and uncomfortable in the batter's box, bearing little resemblance to the potential offensive threat the Mets envisioned after trading for him in the R.A. Dickey deal.

"He almost looks defensive, flicking balls out to rightfield," said one talent evaluator who scouted d'Arnaud extensively in the minors.

D'Arnaud identified the problem early, though the remedies have been as plentiful as they have been ineffective. No matter how much d'Arnaud tinkered with his swing, consistency escaped his grasp.

"He has a bit of a tendency to change a little bit from at-bat to at-bat if something doesn't feel good," hitting coach Dave Hudgens said. "So he's got to find something that feels good and stick with it."

Hudgens has worked with d'Arnaud to get him into a better position to hit. That means eliminating that troublesome shoulder dip. But the two also have tried to establish an approach at the plate.

Before Saturday's game, d'Arnaud sat through an annual meeting with the rest of the team's position players. At the gathering, Hudgens offered a refresher on the organization's offensive philosophy, which places an importance on pitch selection.

In essence, the Mets want their hitters to swing only at pitches they can drive. In the meeting, Hudgens emphasized attacking good pitches, even early in the count.

Hours later, d'Arnaud put the lesson into practice. The first pitch he saw against the Marlins traveled over the heart of the plate, and he didn't miss it.

The ball sailed over the fence in left-centerfield. And for a moment, d'Arnaud savored the feeling of putting it all together.

"It's just a matter of playing time for him, for him to just keep going out there," Hudgens said. "The talent is there."