The Whites have lost their last five Sky Bet Championship games away from Elland Road and have won only twice on their travels this season.
"I think what's happening with us, because of what's been happening away from home, it puts extra pressure on you to win at home," said McDermott.
"You have to try and win that game. If we win the game (against Yeovil) on Saturday then we're looking at the top nine, top eight and then we go to Charlton.
"So if we can win this one we obviously get the feelgood factor back and then the aim is to win three or four games on the spin, which is what we haven't been able to do just yet.
"Playing at home the last game we played very well. We've won the last couple at home. We've got to do all we can to win on Saturday and then we'll look at the Charlton game."