Hoyte, 28, has been heavily linked with Boro's Sky Bet Championship rivals Millwall and his omission against Blackpool on Saturday set tongues wagging.
But Mowbray told the Evening Gazette: "He is behind the others fitness-wise and that is why he wasn't involved.
"No club has phoned me about him. He went to the Gold Cup in the summer and hasn't done pre-season training.
"So don't look too deeply into it. Frazer Richardson and Stuart Parnaby are ahead of him at the moment."