“I don’t know if I’ve ever been around a player who has improved as much as Alex,” Maryland Coach Mark Turgeon said of Alex Len. (Patrick Semansky/AP)

Maryland Coach Mark Turgeon was beginning to tell a story about the “7-foot skinny kid” who walked into his office one day in August 2011 when he pulled out two trinkets from his pocket. They were miniature glass turtles — one representing a child, the other fully grown — given to him by Alex Len’s mother the day the Ukrainian center committed to come to College Park.

“She said, ‘I’m giving you Alex as a baby and when he leaves here, I want him to be a man,’ ” Turgeon recounted Tuesday, when Len discussed his decision to declare for the 2013 NBA draft at a Comcast Center news conference.

“And he’s grown up a lot. In two years, I’ve never seen a kid learn a language, learn the game. . . . I don’t know if I’ve ever been around a player who has improved as much as Alex.”

Just 20 months after Len, 19, took a leap of faith to chase his NBA dreams in the United States, he has quickly morphed into one of the top available big men in this year’s NBA draft class, a status many predicted when he arrived on campus before Turgeon’s initial campaign in 2011.

The 7-foot-1 center was suspended for the first 10 games of the 2011-12 season for a violation of NCAA amateurism guidelines but progressively improved during his time at Maryland. He added 35 pounds to his frame for this season and emerged as a shot-blocking force.

Len averaged 11.9 points, 7.8 rebounds and 2.1 blocks per game this past season and was named to the all-ACC defensive team. He started the year by scoring a career-high 23 points and grabbing 12 rebounds against highly touted Kentucky freshman center Nerlens Noel in Maryland’s season opener, a performance that shot his name up draft boards.

“I think he can be the number one pick in the draft,” Turgeon said of Len. “They’re talking about the other guy [Noel] being number one and you guys saw the same guy I saw when we played them early in the year. This kid [Len] is gonna be special.”

Turgeon said he didn’t try to persuade Len to play another year of college basketball because the prospect of being an NBA lottery pick was too much to pass up. The Terrapins would have brought back seven of their top eight scorers from last season’s team if Len had returned.

“Alex has been a pro every day since he’s gotten here,” added Turgeon, who believes Len’s outside shooting ability will be showcased more at the next level. “I think the NBA game will suit him better than the college game did.”

On that point, Len just smiled when asked if he would miss the double- and triple-teams he faced in the post this past season. “Exactly,” he said, noting he would like to model his game after NBA stars Kevin Garnett and Tim Duncan, two players he watches frequently on television.

But Len added he won’t forget his two seasons at Maryland. Turgeon, along with his mother, helped him make his decision, and Len seemed grateful when his college teammates told him it was the right move after he broke the news earlier this week.

They all knew their Ukrainian Terrapin had grown too big for College Park.

“I know it’s gonna be different . . . it’s gonna be a lot of hard work, but I think I’m ready to compete and contribute to teams,” Len said. “When I came here two years ago, I improved so much that it’s not gonna be hard to make step to the NBA.”