Grabban has netted 11 goals so far this season and is League Two's top scorer after his brace at Barrow in Saturdays FA Cup win.
Rumours had circulated ahead of the tie in the national media of interest from both Sheffield United and Wednesday in the player, but Owls boss Gary Megson said he knew nothing of it.
And Stewart has now confirmed as much, speaking to the Star. “There is no truth behind the speculation whatsoever,” he said.
“We have got some gems as well as Lewis and I have no doubts they will attract predators, but as far as I am concerned my job is to make sure we keep our best players as we are going for promotion whether through the play-offs or automatically.
“We have not been contacted by anyone over Lewis and, if we were approached, we would tell them this is our team and we are moving forward as one and we would turn it down.”
Grabban himself added he knew nothing of the speculation.