The 22-year-old has excelled in Ligue 1 this season and has long been linked with a move to one of Europe's elite sides.
Speculation in England has suggested Arsenal are confident the former Brazil youth international will choose to head to Emirates Stadium for 2020-21.
Lopez expects Gabriel to make a decision soon after suggesting Lille have received at least two satisfactory transfer bids, reportedly in the region of €24million.
When asked about interest from the Gunners, Napoli and Manchester United, Lopez told talkSPORT on Thursday: "That and a couple of more clubs. I think he's narrowed it down.
"I think it's fair to say that Arsenal are a high interest to him, Napoli is a high interest to him.
"We've given him plenty of time to make up his mind. We've always said, 'Look, if we have an agreement with two clubs or three clubs and the agreements are the same then we are not going to create a bidding competition'.
"And that choice, I don't think I'm giving up too much if I tell you that that choice is probably today or tomorrow.
"I'm unable to tell you what that choice is. We've given him some recommendations but we don't like to talk about it in public because we don't want people to feel bad.
"We've talked about where he should go, but at the end of the day he and his environment make a choice and we support that."
Lopez added that he did not want to "speak for the player" about his preferred destination.
Gabriel made 34 appearances in all competitions last season.