Can's deal at Anfield will expire at the end of this season, and the Reds have so far failed to make significant ground during talks over an extension - reportedly due to Can's demand for a release clause to be included.
The 24-year-old looks increasingly likely to leave the club on a free transfer this summer, although he is yet to sign a pre-contract agreement with another team despite having been able to do so since January.
Juventus have long been considered the favourites to sign the Germany international, but Marotta admitted that the Italian champions will have to wait for a final decision on his future.
"We are not going to have a final reply anytime soon. He is a top player and many clubs want to sign him," Marotta is quoted as saying by the Liverpool Echo.
"He is available as a free agent. We've already made our move but his reply is not going to arrive anytime soon."
Can has made 34 appearances for Liverpool this season, including 23 Premier League starts.