WALTHAM, Mass. (AP) – Gerald Green kept sliding down the NBA draft, and the Celtics began to worry. The Houston prep star, projected to be the first high school player chosen, was still on the board as the draft entered the teens and that usually means something is scaring teams away.

Then the trade offers started coming in.

“You start going, Dang! Is something wrong?”‘ Celtics basketball boss Danny Ainge said Tuesday night. “But you should have heard our phone ringing with about two picks to go.”

The Celtics selected Green with the 18th overall pick in the NBA draft, abandoning their plans to get bigger and older when the 19-year-old swingman from Gulf Shores Academy fell out of the top six and into their laps.

“We were positive he would be gone before we had a chance to pick him. As he slid down we kept getting more and more excited,” coach Doc Rivers said. “Why he slid, I couldn’t care less.”

It’s the second consecutive year the Celtics have selected a high school star with their top pick. Last year they made Al Jefferson the 15th overall selection and they were pleased with a rookie year in which he averaged 6.7 points and 4.4 rebounds in under 15 minutes per game.

With the 50th pick in the second round, Boston grabbed another slider: Providence forward Ryan Gomes, who had been projected as high as a late first-rounder. And then they grabbed another player whose name will look good in shamrocks: Louisiana-Lafayette guard Orien Greene.

Green, who was rated the top high school prospect in the nation by at least one respected Web site, averaged 33 points and 12 rebounds as a senior at Gulf Shores.

“This kid can shoot, and he can fly,” Ainge said. “On the downside, he’s 19 and he’s not ready to win in the NBA. I’d be surprised if he beat out our young guards. He’s just another piece for the future.”

Green, who didn’t play as a freshman or sophomore in high school, scored 24 points in the McDonald’s High School All-America Game last year. He also won the McDonald’s slam dunk competition.

“He looked like the dominant player in those games,” Rivers said. “He’s a freak athlete. He has shown that he is a thinker on the floor. An athlete who can think is something any team would like.”

Teams always claim on draft night that they didn’t expect their selection to be available. But this time the Celtics really meant it.

Many mock drafts had Green going to Portland, which picked sixth. But the Trail Blazers picked Seattle Prep guard Martell Webster, and the Los Angeles Lakers, who had reportedly expressed an interest in Green, went with St. Joseph’s (N.J.) High School big man Andrew Bynum.

The Celtics weren’t able to get Green in for a private workout because he was convinced he wouldn’t be around for their pick. Ainge said that 23 different players were convinced they were going to be picked in the top 15.

So the Celtics just waited to see which of them were wrong. New Mexico forward Danny Granger was also expected to be a top 10 pick, and when both he and Green were left after Toronto picked 16th, the Celtics abandoned their plans to get bigger and older.

“We were celebrating in the draft room because we knew we would have one of those two,” Ainge said. “We were begging from 12 on that he (Green) was going to be there.”

Indiana took Granger with the 17th pick and the Celtics, who were already one of the youngest teams in the NBA, took Green.

“We’re going to win the NCAA title next year,” Rivers joked. “Hopefully, we’ll keep getting better and we’ll win the NBA title somewhere down the line.”

AP-ES-06-28-05 2235EDT