Avery Bradley didn’t play a single minute of the 2011 Celtics playoff run that ended in five games against the Heat in the Eastern Conference semifinals, and even before Round 1 of his sophomore season is over he’s already declared himself prepared for the next hurdle in his budding young career. My, how things change.

“It’s been great,” said Bradley of his first four playoff games and his team’s resulting 3-1 series lead. “I’ve been able to learn a lot and gain a lot of confidence. The main thing for me is learning how to approach the playoffs. That was big for me, and now I’m ready; I’ll be ready in Round 2 as well.”

This from a kid who made 8-of-45 field goal attempts outside of three feet as a rookie last season. Bradley had one career 3-point field goal through March 22 of this season. Here’s how far he’s come: Of the C’s first six shots against the Hawks, Bradley took four of them — all outside of 21 feet, on a bum left shoulder.

“It hurt me, but I tried not to think about it,” said Bradley, who left in the third quarter of Game 3 with a recurring left shoulder dislocation. “I just went out there and played hard. I knew my team needed that energy, and that’s what I wanted to bring. It’s been the same. It gets worse as I continue to knock it out, but it’s something that I’m going to continue to get treatment on, strengthen and it’ll get better eventually.”

Celtics guard Avery Bradley gutted through a shoulder injury against the Hawks. (AP)

“I doubt it,” he said. “I just need to continue to get it stronger. I’ve kind of been through it through the season. A lot of people didn’t know it was popping out in practice and stuff, but I kept playing and that’s what I’m going to continue to do. I try not to think about it. That’s my main thing: Don’t think about it; just go out there and play.”

That he did in Sunday night’s victory, starting as usual over Hall of Fame-bound Ray Allen. Bradley scored seven points in 19 minutes and combined with Rajon Rondo on a defensive effort that limited Atlanta’s starting backcourt duo of Jeff Teague and Kirk Hinrich to nine combined points on 4-of-12 shooting and just four assists.

“I felt like we played good team defense, and defense wins games,” said Bradley, whose three personal fouls limited him further. “If we play defense like that, we’re going to be a hard team to beat.”

It’s remarkable to think the Celtics have their best depth at the wing positions of this five-year window. Consider this: Both Bradley and Allen sat with two early fouls, Doc Rivers turned to Mickael Pietrus and the C’s closed out the final 3:54 of the first quarter on an 11-4 run.

It’s even more remarkable Bradley climbed to the top of that shooting guard depth chart under Rivers, whose distrust in youth is notorious. Who would’ve thunk the Celtics could make a fifth straight Eastern Conference semifinals with Bradley as their starting two-guard? First things first: The C’s must win Game 5, 6 or 7 of this series.

“It would be very important for us,” said Bradley of closing out the series Tuesday. “We’ll get a chance to practice a lot more. It’ll be big for us. We’re going to go out there and play the same way we played tonight.”

And what way is that?

“We had a lot of fun,” added Bradley. “It’s fun playing the right way, playing the Celtic way, and that’s what we did.”

Imagine that, Avery Bradley, NBA veteran, already schooled in the ways of the 17-time champions.