Phillip Danault was a first-round draft pick in 2011, but didn't see more than two games of NHL action until this season. He missed time at the beginning of the year after undergoing hip surgery, started his year with the Chicago Blackhawks, and was eventually traded to Montreal ahead of the deadline. With both clubs he was used in a heavily defensive role, which he filled well while managing to also contribute some points.
Danault was of course acquired by the Canadiens back in February, the main piece sent from Chicago in return for Dale Weise and Tomas Fleischmann.