The Calder Memorial Trophy is awarded to the League's top rookie.
Gallagher, who is celebrating his 21st birthday Monday, had 15 goals and 13 assists in 44 regular-season games for the Canadiens. A fifth-round pick (No. 147) at the 2010 NHL Draft, Gallagher has two goals in the first three games of Montreal's first-round series against the Ottawa Senators in the Stanley Cup Playoffs.
Huberdeau, the No. 3 pick in 2011, finished second on the Panthers in scoring with 31 points (14 goals, 17 assists) in 48 contests. Huberdeau tied for first in rookie scoring with Edmonton Oilers winger Nail Yakupov, who was the No. 1 pick in 2012.
Saad, 20, tallied 27 points (10 goals, 17 assists) in 46 games for Chicago. A second-round pick (No. 43) in 2011, Saad began the 2012-13 campaign with the Rockford IceHogs of the American Hockey League, where he went 8-12-20 in 31 contests.
All of this season's award winners will be announced during the 2013 Stanley Cup Final, with more detail on format to be released at a later date.