Merrill, 22, has not practiced since a head-to-head collision with Ruslan Fedotenko last Friday. DeBoer said Merrill would be practicing if it were the regular season.
Merrill had two goals, nine assists and 11 penalty minutes during his rookie season with the Devils. He was a second-round pick in the 2010 draft by New Jersey.
The Devils finished last season 35-29-18, missing the playoffs by five points. They open the regular season Oct. 9 against the Philadelphia Flyers.
- Paul Palladino