The 68-year-old, who stood down as coach in 2012, says he is ready to replace Vladimir Petkovic at the helm of the Biancocelesti.
Current coach Vladimir Petkovic has yet to be officially removed from his position, but the 50-year-old, who has been under pressure because of the capital club's poor performances this season, announced earlier this month that he had agreed to take charge of Switzerland after next summer's World Cup.
It has been widely reported that Biancocelesti president Claudio Lotito had lined up Reja as an immediate replacement and the former Napoli coach has publicly stated that he is looking forward to going back to Rome.
"Lazio and I can achieve some great things together, already from this season,” the 68-year-old told La Repubblica.
Reja spent two years at the Stadio Olimpico before resigning as Lazio boss in the summer of 2012 - despite the best efforts of Lotito.