Preston North End are set to take on Sheffield Wednesday at the weekend.
The Owls brought in Aiden McGeady from Everton and Gary Hooper from Norwich City in the previous transfer window.
And Grayson believes that the capture of those two players shows just how determined Wednesday are to make it into the Premier League.
“They've gone out and recruited from the summer, built again in the January window with the signing of Hooper, McGeady from Everton, and these are all top, top players and they've got one ambition which is to try and get into the Premier League,” Grayson said.
Preston are set to take on Wednesday on Saturday, as two of the Championships in-form sides meet at Deepdale.
Wednesday will be backed by over 5,000 fans in the contest and Grayson is under no illusions as to how difficult it will be for his side to pick up the three points.
"We know it's going to be a test for us but we've really enjoyed the big games and big atmospheres this year," he added. "The last biggest one we've had was the Hull game, where every man of ours played very well and got the victory so hopefully that's the case again on Saturday."
Wednesday have collected more points than any other Championship side over the last 10 matches, and they have elevated themselves into promotion contention as a consequence.
The Owls are currently stationed in fifth place in the second tier, and if they are able to beat Preston they could move to within two points of the automatic promotion spots.