Amrabat made his return in the Hornets' 1-0 defeat at Crystal Palace, having been out since the turn of the year, and Deeney is confident the Moroccan's return will have a positive impact on Watford's poor run of form.
Deeney told the BBC: "We have some quality coming back off the bench with Nordin coming back. We've got two weeks to work hard and go again."
The Hornets, who are seven points clear of the drop zone with ten games remaining, have won just two of their nine Premier League games since Amrabat limped off against Tottenham Hotspur with an ankle ligament strain on New Year's Day.
The 29 year-old, who underwent part of his rehabilitation in Holland, was influential in the first half of the season, managing three assists before the injury that also kept him out of Morocco's African Cup of Nations squad.
Amrabat replaced Daryl Janmaat after 60 minutes in Saturday's defeat at Palace, but was unable to prevent Watford from slipping to their 13th defeat of the season. The winger will be in contention after the international break when the Hornets host Sunderland in a crucial fixture in the race for Premier League survival.