The 23-year-old proved to be Spain's hero in this summer's Olympic final against France, coming off the bench to register twice in what was a 5-3 success for La Roja.
Having returned late to pre-season training, Camello has been used twice off the bench in La Liga this season, providing an assist in his side's 2-1 success over Real Sociedad on the opening weekend.
Camello then featured for the final 18 minutes of the goalless draw with Getafe last time out, but the striker is expected to come into the starting side for Rayo's third game of the new season.
Rayo will again be missing Andrei Ratiu due to a muscular problem, but the visitors, who have four points from their two league games this term, are otherwise in excellent shape.
As well as Camello, there could be a spot in the starting side for Isi Palazon, with the Spaniard potentially coming into the XI to replace Oscar Trejo.
Head coach Inigo Perez is unlikely to make any further changes, though, with Jorge de Frutos and Adri Embarba again expected to operate in the wide positions for the capital side.
Rayo Vallecano possible starting lineup: Cardenas; Balliu, Lejeune, Mumin, Espino; Valentin, Ciss; De Frutos, Palazon, Embarba; Camello