However, the Iron boss thinks the club might not be able to afford the player's wages.
Bristol City defender Ribeiro has already said he would welcome a return to the Iron, where he spent two months on loan last season, making 11 appearances.
Knill told the club's official website: "I've spoken to his agent this week and he has some offers. They're pretty good offers as well I have to say.
"If I'm going to be totally honest we haven't actually put an offer on the table yet. But when I spoke to his agent, who I know really well, and he told us the figures involved, they were quite high.
"Saying that, he's taking a big cut [on his previous wage at Bristol City] to get down to those figures. But even that's more than we could afford.
"Some of the offers he's had are a lot closer to home, which in some ways may be better for him as a person, but I'll speak to Chris in person and see what he's thinking."
