The Providence Journal reports Warsofsky joined the team for practice Thursday morning.
Before joining BU, Warsofsky was captain of the 2007-08 US National under-18 team and won a bronze medal in the U-18 World Championship. He also won a gold medal as part of the US Team at the World Junior Championship in 2010, becoming the only BU player ever to win gold at the event.
Over his three-year career as a Terrier, the defenseman scored 17 goals and added 34 assists.
The Bruins acquired Warsofsky, a Mansfield native, last summer from St. Louis for Vladimir Sobotka.
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