Bournemouth boss Eddie Howe rates the Owls as “dangerous opponents.”
That is because he regards them as being under no real pressure now that they are virtually safe.
The Cherries, on the other hand, must win to be sure of keeping their play-off hopes alive.
Howe, who worked with Gray briefly at Burnley, said: “Stuart has done a great job. He took on a difficult task as they (Wednesday) had been a little inconsistent during the early stages but he has put together a really good run and they have been one of the form teams in the second half of the season.
“They are dangerous opponents for us. They will not be going down and will not be involved in the promotion battle either. They will come here with that freedom of a team which wants to spoil our party and that is what will make them dangerous.
“Stuart has got them playing good football. They have changed their style slightly and have some good players. They have brought in a couple of good loan players as well and have real experience in their squad. They have players who have been there and done it at this level. I think we know what to expect from them but they have real quality in the front areas.”
Bournemouth rose into contention for the play-offs with five successive wins, including results against fellow promotion hopefuls QPR and Reading, before they drew 1-1 at Yeovil last week.
Howe added: “We knew Yeovil was going to be as tough a game as QPR and Reading. Nobody gives you anything in this league and every game is a potential defeat if you are not at your best. “We know our energy levels dipped against Yeovil and the games against QPR and Reading took a lot out of the players. I hope we get our zip back for Sheffield Wednesday.
“We are under no illusions that we need to match the levels we showed against QPR and Reading if we are to get a positive result.”
Unlike Gray - who will be 54 tomorrow - Howe has a full-strength squad.
Top scorer Lewis Grabban is expected to play after being taken off at Yeovil owing to tiredness.
Howe added: “The squad is looking in pretty good shape. Lewis had been fatigued from the run of games we have had and we certainly need to be careful with him.
“We have a very talented squad.”