Ethan Happ is one of college basketball's most efficient players, but can he adapt to the modern NBA?

How can one of college basketball’s most efficient player for two years running not have a place in the NBA?

Wisconsin’s Ethan Happ is just one of three players and the only one from a major conference to place in the top-10 in Player Efficiency Rating in each of the past two seasons. He dominated the Big 10 last year and averaged 17.9 points per game — the third-best mark in the league. Happ’s sky-high 34.6 percent usage rate and the measly 97.4 points per 100 possessions that Wisconsin allowed when he was on the floor last year speaks to how valuable the 22-year-old was for the Badgers on offense and defense.

But the 6-foot-10 big man with a refined back-to-the-basket game is only generating late second-round interest. The Nuggets, who worked out Happ Tuesday morning, sent him home with the same message that every team he’s visited with so far in the pre-draft process has.

“You’re an elite passer for a big. You can really finish around the rim, but for you to take that next step you have to get a 10- to 15-footer down,” Happ said relaying what teams have told him over the past few weeks.

Happ converted 242 field goals last season but just 11 of his makes came from outside the paint. He converted one of his 11 three-point attempts and was 1-12 on shots from what TheStepien.com defined as the “long mid-range.”

He’s a patient scorer when he receives the ball on the block and is adept at getting his opponent in the air with a simple shot fake. But Happ can distribute too. The 3.7 assists per game he averaged last season speaks to his vision, and the 200-plus assists he’s racked up over the past two seasons is an impressive total for a big man on a Wisconsin team that doesn’t exactly play with a sense of urgency on offense.

Happ effectively balanced playing the role of go-to scorer while rarely forcing his own offense. It’s a similar harmony to what Nuggets star center Nikola Jokic achieved over the past two seasons — a player Happ says he models his game after.

“The Joker, honestly I’ve gotten some comparisons,” Happ said. “Obviously, he’s a much better shooter but with the passing and the ball handling for our size.”

As the NBA’s sharpshooters stretch further and further out past the three-point line, the league’s big men have followed their lead. Nowadays it’s difficult to run an NBA offense with more than one non-shooter on the floor. Try and play two or three non-shooters at a time and fast-acting defenses will scheme on the fly and force those players off the floor.

It’s no longer a luxury to have a power forward or center who’s able to stretch the defense out to the three-point line. In many cases, its become a necessity.

This past regular season, NBA players 6-foot-10 or taller shot 10,814 threes, per NBA.com/stats. That’s up 671 threes from last year and a staggering 4,326 threes from the 2015-16 season.

“I know the thing that I have to work on. This is a whole different game in the NBA,” Happ said. “I’m really efficient at finishing around the rim, and I’m a good passing big, but that’s not going to get you into the spots that I want to be in in the NBA.”

Aron Baynes, whose Celtics find themselves deadlocked with the Cavaliers 2-2 in the Eastern Conference Finals, attempted seven three-pointers over the first five years of his career. This season he shot 21 threes. In 16 playoff games, he’s already 11-21 from distance.

Right now, Happ is glued to the paint on offense. Developing his jumper has been his main focus since his college season ended, but it’s still a work-in-progress.

To get an upper hand on his competition in group workout settings, Happ studies other players’ isolation possessions that he’s going up against on the popular Synergy Sports application, which catalogs video of every NCAA players’ possessions throughout a season.

“I’m diligent in my work,” Happ said. “I like to get the most advantage that I can before I can come in for workouts.”

Happ hasn’t hired an agent and could still return to Wisconsin for his senior season. He has until May 30 to withdraw his name from the draft and return to school. If he does return to Madison, developing his jumper will surely be high on his to-do list.

“It’s tough because I’ve had a lot of interest talking with teams being a late-second round draft pick,” Happ said. “But I’m a fan of college basketball as well and think I can really develop there. I’d like to get higher up, late first (or) earlier second, but that’s not what it’s looking like talking with teams. So we’ll make a decision after these next three workouts.”