Midfielder Milinkovic-Savic reportedly has a verbal agreement to join Premier League giants Man Utd, with Ander Herrera having left for Paris Saint-Germain and Paul Pogba's future uncertain at Old Trafford.
According to reports, United are ready to offer £82 million ($100m) to prise Milinkovic-Savic from Lazio – who signed the 24-year-old Serbia midfielder in 2015.
"As I said a long time ago, it doesn't matter how hard it could be [to keep Milinkovic-Savic]," Lotito told Sky Sport Italia .
"We will see what the market can offer and all the conditions that are going to be.
"We [as a club] feel great with Milinkovic, as he feels with the club. Offers, if there will be any, will be considered in a spirit of cooperation in order to guarantee both the interests of the club and the player."
Lotito has previously admitted he expects it to be difficult to keep hold of the club's star midfielder after he turned down interest from a number of teams last year.
Lazio head coach Simone Inzaghi has echoed that view , admitting it will be difficult to ward off competition for the Serbian's signature.
The Serie A side made a number of signings last season after selling winger Felipe Anderson to West Ham for £36m ($44m), most notably bringing in Joaquin Correa from Sevilla.
Despite that recruitment drive, Inzaghi's team had a disappointing season, finishing eighth in the Italian top flight.
"The investments we made last summer should’ve allowed us to qualify for the Champions League, but we hope to have learned from the experience," Lotito added.
Manchester United boss Ole Gunnar Solskjaer could eye Milinkovic-Savic as a replacement for Paul Pogba if the France international were to leave Old Trafford.