Mowbray signed Miller during his time as West Brom boss, but is not planning a reunion with the former Manchester City youngster.
"I know we've been linked with Ishmael Miller, but I'm not sure where that's come from," said Mowbray on the club's official website. "There's no substance in it.
"I think people are just putting two and two together because I signed Ishmael when I was at West Brom and they are thinking of making him available on loan. But I've not had a conversation with them."
Mowbray is also intending to assess the likes of Marvin Emnes and Andrew Taylor, who are currently on loan at rival Championship clubs, upon their return to Teesside.
He added: "I'd like to take a look at all of them and assess them, to be fair to the whole squad.
"But Marvin is on a 28-day loan and we can't bring him back before that, while Watford aren't going to agree to Andrew Taylor coming back so it is what it is.
"It's only fair to the players who are out on loan to bring them back and assess them. We will certainly send someone out to have them watched where they are, but I would prefer to have them back here."