After suggestions Ligue 1 side Nice have jumped to the front of the queue in a bid to loan Roberts before Monday's deadline to register new players for the Champions League play-off round, the Scottish champions insisted they are still hopeful.
Celtic assistant manager Chris Davies stressed there is a place at his club for the 20-year-old, who previously spent 18 months on loan in Glasgow, if he wants it.
Davies revealed Celtic remain in talks with City, telling reporters: "We really enjoyed working with Patrick, there is always going to be a home for him here if that suits everybody.
"They have been talking and the situation is always open to a certain extent because the transfer window is still open.
"We've got the players that are with us working and fighting right now, we've been scoring and creating goals, so if something extra happens then it's all positive, but if not we're OK.
"All I know from our part is that we value the player, rate the player, and I'm sure if it was right for everybody then something would be done. But we can't really control that at the moment, we just focus on our work here and see how that one evolves.
"Pat at the moment is playing for Man City, he's featured for them, so I can't comment too much on it. All I can tell you from my side and speaking for the manager is how much we enjoyed working with him, and the rest will take care of itself."
Roberts played 47 games in all competitions last season, scoring 11 times as Celtic won a domestic treble for the first time since 2001.
Nice have been busy already ahead of the Champions League deadline, completing the signing of free agent Wesley Sneijder.