Posh Alexander made a guarantee: He’s not going to be afraid of letting it fly this year.

Not if he misses a few shots. Not if the ball doesn’t fall in a certain game. St. John’s junior knows this is a big year for him, and he will enter it with his confidence soaring.

“I just can’t wait to show everybody how I shoot this year,” Alexander said on Thursday during St. John’s media day.

He spent the entire offseason preparing for it, working on his shot like never before, dedicating his summer to improving the major weakness in his game. The 6-foot Brooklyn native took the Big East by storm as a freshman, named the league’s Freshman of the Year and co-Defensive Player of the Year. He put up strong numbers as a sophomore, averaging 13.8 points, 5.5 assists and 2.3 steals, but he didn’t take the leap some expected. His 3-point shot fell to 21.7 percent from 29.9 percent, making it far easier to defend him.

That didn’t sit well with the dogged defender. And with Julian Champagnie’s departure to the NBA, Alexander knew the spotlight would be on him. He had to make a change, and so he began spending extra time in the gym, working out multiple times a day, visiting his old high school, Our Saviour Lutheran, to work on his jumper. He is now at 198 pounds, down from 215 as recently as May.

“My mindset was a lot different,” he said. “I’m maturing, I’m seeing life differently. I wanted to work on getting in the best shape I could. … I’m trying to take it to another step and be the best version of myself. Last year motivated me a lot. I feel like I have a lot more to prove this year.”

There were a few reasons for his shooting struggles. Alexander dealt with various leg ailments and was often limited or held out of practice, cutting down on his reps. Without another true point guard on the roster, he was overburdened with extra responsibility. This year, that will be lessened following the addition of Illinois transfer Andre Curbelo.

“I just think the makeup of this team allows him to do more things,” coach Mike Anderson said.

Alexander is excited for the coming season, repeatedly saying he is honored to share a backcourt with Curbelo, eager to showcase his improved jumper and conditioning. For St. John’s to reach the NCAA Tournament, Alexander will have to lead the way.

“I feel like personally I’m ready to have a big year,” he said, “and I think this team will have a big year.”