Shelvey hasn't featured for the club since the December 1 game against West Ham United at St James's Park.
However, the midfielder has been passed fit ahead of the club's game against Watford.
The only two players in the treatment room are Ciaran Clark and Karl Darlow, while Ki Sung-yueng is away with South Korea ahead of the Asian Cup.
Asked about injuries, Benitez said: "Clark and Darlow both are still not available – the rest of the team is available, even Jonjo. We have bodies available."
Newcastle are 15th in the Premier League.
More to follow