Ellis made his NHL debut last season, playing 32 games for the Predators with 11 points (three goals, eight assists). The defenseman was the No. 11 pick in the 2009 NHL Draft.
Watson, a forward who was the No. 18 pick in the 2010 NHL Draft, had 35 points in 29 games for London of the Ontario Hockey League last season.
Also assigned to Milwaukee were forwards Daniel Bang, Taylor Beck, Gabriel Bourque, Patrick Cehlin, Kevin Henderson, Jani Lajunen, Michael Latta, Jack MacLellan, Juuso Puustinen, Ben Ryan and Josh Shalla; defensemen Taylor Aronson, Victor Bartley, Anthony Bitetto, Mattias Ekholm, Joonas Jarvinen, Charles-Olivier Roussel and Scott Valentine; and goaltenders Magnus Hellberg and Jeremy Smith.
The Predators also loaned Colton Sissons to the Western Hockey League’s Kelowna Rockets.