By the time the Bruins picked at No. 9 tonight, Dougie Hamilton, Ryan Murphy and Nathan Beaulieu — three coveted defensemen — were still on the board.

So Bruins general manager Peter Chiarelli had a difficult decision.

Boston went with Hamilton, with its first pick in the 2011 NHL Entry Draft in St. Paul, Minn.

At 6-foot-4, 187 pounds, Hamilton is by far the largest defenseman the Bruins have drafted in the Chiarelli era.

Here’s a scouting report on the 18-year-old blueliner from NHL.com:

NHL Central Scouting’s Chris Edwards

“He moves the puck well and makes good outlet passes, he does make good decisions with the puck, moves it very well out of his zone. He’s a big guy, he’ll take the body. … He uses his size well. He can muscle people off the puck.”

Niagara IceDogs head coach Marty Williamson

“Especially at this level, you find guys that are awkward or don’t have a lot of explosion. You’re 6-foot-4, you don’t have a lot of explosion (but) the jump off his skates is phenomenal. When he sees those opportunities to jump into the rush or lead the rush, I really believe it’s untapped what he can do. He’s a very special defenseman in our league. He just has to understand the details and he’s going to be a very good pro . . . Dougie gets himself very prepared for hockey games. He’s very diligent preparing himself. He goes about it very business-like. He’s mature beyond his years.”

Rumors abounded leading up to the Bruins’ pick, which was the last piece of the Phil Kessel trade with Toronto, that Boston was going to trade the pick to Nashville for prospect Ryan Ellis. But Chiarelli made the puck and as of 8:35 p.m. EST there was no trade to announce.