Milan Lucic agreed to a three-year, $18 million extension with the Bruins on Saturday. The deal will kick in after this season. In terms of average annual value, the 24-year-old will now become the highest-paid forward on the roster. The physical forward had 26 goals, 62 assists and 135 penalty minutes last season. In about a week, the Bruins have locked up three key forwards: Lucic, Tyler Seguin and Brad Marchand.