The Ghana winger has been out of action since straining a muscle while attempting a shot in a league fixture against Bournemouth last month.
Having been ruled out as a serious injury, the 25-year-old suffered a relapse while on international duty with Black Stars and had to be sent back to his club.
Ahead of their tie against a resurgent Leicester side, Benitez whose team have picked just a point from their last six top-flight games, welcomes Atsu and defender Jamaal Lascelles.
“Lascelles and Atsu, they are available. Dummett will play with the Under-23s today [Friday] to improve his match fitness,” Benitez said.
"We had some problems and now we are bringing back players and that is good news, because – in the end – I always say the same: the competition between players is the key for us."
Atsu will be looking to earn his 12th English top-flight cap this term when Claude Puel's side visit the St. James Park on Saturday.
The former Chelsea winger has found the back of the net once in 915 minutes for 15th-placed Newcastle.