Royals' trip to St Mary's this weekend has been billed as a relegation six-pointer between two sides in the bottom three.
Reading are currently 19th in the Premier League table, three points behind Saints with a game in hand.
However, McDermott declared: "On Saturday we are playing for three points and that is it. People will try and blow it out of proportion, but it's nonsense to call it a 'must-win' game or anything like that.
"It's just a game of football we will try and win. That's how I've approached games for a long, long time.
"There is no more pressure on the Southampton game than there was on playing Manchester United last weekend, or on trying to win at Barnsley last season come to that."
While McDermott is eager to deflect the pressure away from his players, Reading fans fear the week ahead could shape their entire season.
battle on the south coast, Royals then make the long trip north next Tuesday to face fellow strugglers Sunderland in a re-arranged fixture at the Stadium of Light.
And with Martin O'Neill's Black Cats sitting one position above Southampton, it is another game Reading cannot afford to lose.
"It's two away games and a fair amount of travelling in the space of four days," added McDermott. "We hope to do ourselves justice and come out of it with some points.
"We're trying to nail things down defensively so we don't ship as many goals as we have been recently and we're working extremely hard on that.
"We're trying to do the best we can for the fans and I believe we're improving all the time.
"We've played 14 games now so we know what the Premier League is all about."
Nigel Adkins' Saints have stolen an early march on Reading with three wins under their belt to Royals' one.
But history is on Reading's side as McDermott's men are yet to lose on three visits to St Mary's.
Their last visit was also a memorable one when an Adam Le Fondre brace and Jason Roberts strike secured a 3-1 victory in April which sent Royals top of the Championship table, a position they would not
relinquish from there.
"That win put us above Southampton, it was a special day," recalled McDermott. "But this is a new season now and a different league. We will go there and try to win, like we do every game."
McDermott knows that improving his defence will be central to their survival chances.
Having shipped seven goals against Arsenal in the Capital One Cup recently, Royals twice threw away a lead last Saturday in a 4-3 home defeat by Premier League leaders Manchester United.
"I thought we should have got something from the Manchester United game," he argued. "We need to defend better as a group now, it's as simple as that.
"The hardest thing in the Premier League is scoring goals and we're managing to do that. But we have to make sure we keep clean sheets.
"We have also got to remember we are playing against the likes of Wayne Rooney and Robin Van Persie here, the top players in the world.
"I spoke to Sir Alex Ferguson and he said he was just happy to get out of there with a win. But the fact is we have given every team a good game, we've got to start picking up the right results now."