The Argentine attacker moved to Claudio Ranieri's side on a temporary deal in the summer, but the capital-city club have stated that he may come back to the Stadio Olimpico
The Argentine striker left the Stadio Olimpico in acrimonious circumstances, as a fallout between player and trainer was reported in the Italian press.
The 24-year-old has had an inconsistent time at the Giuseppe Meazza, scoring just once this campaign, and Claudio Ranieri's men are believed to be ready to reject the option to buy the forward come the end of the season.
Despite the nature of Zarate's departure, the 66-year-old trainer is willing to consider the South American's return to the Italian capital.
"We have not dealt with this yet, but we can talk about it and will evaluate [our options]," the former Napoli coach is reported by Calcio Mercato to have said.
"I know it is a central role, although we have already [Libor] Kozak, [Djibril] Cisse, [Miroslav] Klose and [Tommaso] Rocchi playing in his position," he stated.
Lazio return to action with an away fixture against Siena on Saturday; Reja is looking to get back to winning ways after a welcomed break.
"There's always a question mark when you resume after a break," he admitted.
“Siena are an aggressive team but we have the expertise to exploit the space they leave.
“Eight to ten days of rest have helped us mentally and physically," Reja concluded.
Lazio are currently one position above Inter in the Serie A standings, four points clear of Ranieri's men in fourth place.