"Right field's become a fair ball for him," said Trembley, speaking of one clear improvement. "He's gotten a lot of base hits the other way. He's shown improved patience at the plate, not chasing the first pitch. He's become a much better two-strike hitter. And when I say right field's become a fair ball for him, I mean he's used the whole field a whole lot better."
Jones, who's fit in as a semi-permanent fixture in center field and at the bottom of the batting order, has noticed how opposing pitchers want to beat him. He said that pitchers have recognized his weakness at hitting the offspeed pitch and have made sure to attack him early in the count, an approach that has caused some adjustments of his own.
"I'm seeing 1-0 sliders [and] 1-0 changeups instead of 1-0 fastballs," he said Wednesday. "I've just got to stay patient and take it. They have to throw a fastball at some point in time. If I can lay off that junk they are throwing me ... that's it. I've seen at-bats and looked at video where I got one strike and swung at three or four balls. If I lay off them, it's 3-1."
Trembley has said that's part of the normal learning curve for young hitters, who don't necessarily see that same kind of breaking pitch in the Minor Leagues. Games are won or lost on the fastball in the Minors -- both offensively and defensively -- and most hitters have to learn how to deal with the breaking ball once they graduate to the Majors.
Typically, according to Trembley, that often turns young hitters into being overaggressive at the plate.
"A lot of them don't want to get behind in the count, for one," he said. "And two, they don't want to get jammed. Three, once they get the fastball to hit and don't hit it, they have a tendency to get somewhat frustrated and chase pitches.
"[Adam is] a young guy and when pitchers get ahead of him, they have a tendency to expand the strike zone. ... I think he's kind of stayed away, lately, from getting himself out and chasing pitches that aren't strikes."
Jones acknowledges that phenomenon, but he said that he tries to keep it as simple as possible at the plate. He's learned a subtle mantra from hitting coach Terry Crowley that says everything he needs to know.
"Just keep swinging. Go up there and get a good pitch to hit," he said. "If it's the first one, hit it. If it's not, just try to wait and get a good pitch to hit. Don't go out of the zone. That's what I'm trying to do."
Jones, who had his first four-hit and four-RBI game on Tuesday night, said that hitting requires a strange dichotomy. You have to be aggressive, but you also have to make sure that you're not swinging out of your shoes.
"It's tough to hit," he said. "You get yourself in that box, you don't know what's coming and you want to be aggressive. Especially in RBI situations, I try to relax even more because he's in trouble, not me.
"I try to stay back and make them come to me, instead of me going out and trying to attack something. Because the first pitch, they're going to throw something offspeed, and I end up chasing it in the dirt or off the plate."
The approach hasn't shown up in statistics yet -- Jones had a .272 average and a .320 on-base percentage in April and has a .268 average and a .305 mark in May -- but it has succeeded in making the youngster more comfortable. And so had the rowdy atmosphere of the clubhouse, which has assimilated him into its crowded cast of characters.
"Everybody is comfortable with everybody," said Jones, who was acquired from Seattle in the offseason trade for Erik Bedard. "Everybody is always running around yelling. The camaraderie is awesome.
"I know that goes along with winning, and it's easy to play when you are playing good. But even in that last road trip when we had a little downfall, everybody was still the same way. I've never really been around a clubhouse like that."
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.