Big day of d-man signings in Philly — shortly after the club inked Andrew MacDonald to a six-year, $30 million extension, the Flyers announced they’ve agreed to terms with Union College standout Shayne Gostisbehere.

Gostisbehere, 20, was taken in the third round (78th overall) at the 2012 NHL Entry Draft and has spent the last three years at Union, helping the Dutchmen win their first-ever NCAA national title over the weekend with a 7-4 victory over Minnesota.