Etem and Smith-Pelly each had one goal and two assists for Norfolk on Wednesday night.
Coach Bruce Boudreau said though each of the 21-year-olds will benefit from increased playing time, the move is also a reminder of the first-place team's demand for consistency.
Etem scored his sixth goal Tuesday, but also let Dallas' Cody Eakin skate past him to score a third-period goal that started the Stars' three-goal blitz in 53 seconds in the Ducks' 6-3 loss. Smith-Pelly has a goal and seven assists in 16 games.
"We need them to play on a consistent basis," Boudreau said. "This league is too tough. We don't know if it's going to be long-term or short-term, but the last time we sent Emerson down he came back a much better player and we're thinking that's going to happen again."
One of the roster spots could be filled by veteran center Saku Koivu, who was cleared for the first time for contact at the Ducks' Wednesday practice. Koivu said that barring any unexpected symptoms from the Oct. 27 concussion he suffered in Columbus, he expects to play in the Ducks' 1 p.m. Friday home game against Calgary.