A bumper crowd - including 4,500 visiting supporters from Wearside - will converge at Oakwell - as the second-placed Reds seek to secure another victory and move seven points clear of the Black Cats, although the north-easterners will still have a game in hand.
Should Barnsley also go unbeaten, then they will extend their unbeaten sequence on home soil to a calendar year.
Tonge, who reports no fresh injury issues from the 2-0 victory over Accrington, said: We are under no illusions, it is a massive game. We have had fan mail from America, somebody from Wisconsin, sending things saying they are looking forward to the game, anticipating a good game, so it just shows it's a big game.
"We are going to look forward to it as I am sure Sunderland are. It's a big game in terms of positioning so we are going to take it head on like we do every game and enjoy it.
"The boys are well aware of the situation, it is not something that is new to them, it is just being about calm in the situation and producing what is needed."
"It is a big game, we are well aware of that, we can increase the gap and they can close the gap but I don't think this game is the be all and end all for the promotion race.
"We look at it as a must-win game for us, let's win the game and let the rest take care of itself."