BOURBONNAIS, Ill. — Anthony Miller, on the surface, did plenty of impactful things as a rookie in 2018. He led the Bears in touchdown receptions and made a handful of other big plays for a playoff team, flashing the upside that enticed the Bears to trade back into the second round to draft him.

“Knowing that I did that last year with what I was going through,” Miller said, “I just know it has to get better from here, just because I’m better mentally and physically.”

The physical things Miller went through in 2018 were plain to see: His shoulder dislocated multiple times, including on a Week 17 end-around against the Minnesota Vikings on which he wasn't hit. He gritted through the pain and missed only one game, then underwent an offseason procedure to keep his shoulder from popping out.

“It’s nice knowing that I can just run freely and do things without having to worry about that,” Miller said.

So that’s where Miller is physically better. The mental side of things is less obvious, yet is just as — if not more — important.

Miller said he was late to a few workouts during his rookie season as he struggled to create a set routine and develop a schedule. For a guy who was drafted in 2018’s second round with a reputation as a hard worker, it was a little surprising to hear that. But while Miller was snagging touchdowns and dancing in end zones, he struggled to acclimate to his new life in the NFL.

“I just think I came in with so much freedom and I’m getting paid and I’m just this young guy, I don’t know, trying to embrace it all,” Miller said. “And from knowing the plays to being here, being there, I just had to get a good grasp of the schedule and everything like that.

“… Every rookie goes through that phase where they spend money on stuff and they’re going out, they’re doing all this type of stuff. You just gotta learn how to prioritize your time, and that’s what I’ve been learning to do. I’ve been watching older guys do what they do as far as rehab, recovery, studying and stuff like that and now I’ve incorporated that into my daily routine. So I’m just getting better and better with that.

“But I got it down pat now. No mistakes.”

Miller finished his rookie season with 54 targets, 33 catches, 423 yards and seven touchdowns — decent, yet not great, production for a rookie. A three-game lull in December might’ve been the best representation of Miller struggling to get the mental side of things down: He was targeted just three times in three games between Weeks 12-14, catching one pass for one yard (which, to be fair, was a game-tying touchdown against the New York Giants).

Offensive coordinator Mark Helfrich admitted at the time the Bears probably “overloaded” Miller, and then had to throttle back his workload. It was, perhaps, a bigger-picture wakeup call to Miller: The Bears remained high on his potential, but just because the team invested extra draft capital (a second-round pick and a 2019 fourth-round pick) to get him wasn’t going to guarantee him a prominent spot in the offense.

“I learned just to be on top of your stuff, man,” Miller said. “Nobody’s going to tell you to do this and that at that time. You just gotta be on top of your scheduling, be on top of everything, man, because they’ll let you go. It don’t matter how good you are, who you are, you know what I mean — you’re seen it in the news, like, they cut top guys and you wonder why. It’s something behind the scenes that they’re not doing.

“I’ve learned that this is a ‘we don’t need you’ league. You know what I mean? They want you, but they don’t need you. I just go into every day with that mindset.”

Not every player comes across as self-actualized as Miller, or realizes these things as quickly as he did. For some players, it takes three or four years; others never do and fade out of the league despite their talent.

So without worrying about his shoulder popping out and carrying a fresh mindset, Miller doesn’t see why he can’t build on what he did as a rookie. He doesn’t set specific goals for himself, knowing the talent around him means he could go off one week and not be targeted much the next. The expectation, more than anything else, is to be a part of an offense that’s much improved in 2019.

“It's fun for me to see from the quarterback position because he's starting to understand where he fits within each scheme, he's understanding timing a lot better and he's seeing the big picture on the offense side,” quarterback Mitch Trubisky said. “And I think that's helping him on his individual routes and getting the ball in open space.”

Coach Matt Nagy estimated 85 percent of the reason why plenty of wide receivers make a leap in production from Year 1 to Year 2 in the NFL is due to a better grasp of the mental side of things. And he was pleased with how Miller went about his business during spring’s two-month offseason program, when he wasn’t practicing but remained engaged in everything else the team did.

“I think to his credit — he had a chance to go through that in the offseason here with his injury,” Nagy said. “He was able to be in meetings and really dive into that playbook. Now we get into training camp and he has double duty with the physical side and the mental side. So far, from what I’ve seen, it’s what we thought we’d have when we drafted him.”

And what the Bears thought when they drafted Miller was they found a receiver with explosive playmaking ability and 1,000-yard upside. With the physical stuff healed and the mental stuff dealt with, Miller sees no reason why he can’t live up to that sky-high potential.

“I just had to learn my lesson, man,” Miller said. “This year I came in with the mentality of not making those type of mistakes anymore."

Click here to download the new MyTeams App by NBC Sports! Receive comprehensive coverage of the Bears and stream the ‘Football Aftershow’ easily on your device.