Boston signed a pair of AHL defenders on Friday as it announced Michael Callahan has signed a one-year, two-way contract extension to remain with the Bruins. The 24-year-old has yet to make an NHL appearance after spending the previous two seasons with Providence (AHL) after joining from Providence College (NCAA) in 2021-22. In 70 games in 2023-24 he had four goals and 17 points.