Spurs have failed to win six of their nine games following a European outing - the latest being Sunday's 1-0 defeat at Norwich which left them six points adrift of Liverpool in fourth.
That loss followed a 1-0 reverse to Dnipro, which Tim Sherwood's side will attempt to overturn in the second leg at White Hart Lane on Thursday night.
But Naughton insists Spurs have the squad to cope with both competitions heading into the final weeks of the season.
"We can't make excuses about playing in the Europa League. That's what we are in, we should have a big enough squad to deal with that and the Premier League," said the defender.
"The stats don't lie, it does seem that way, it's something that is happening and we're not sure why.
"The games are running out but we have got to keep fighting, we can't let that go. We have to aim for the top four.
"It's difficult at the minute, everyone is doing quite well above us. But we are looking above us rather than behind us. We are not looking to catch an individual team but to just get as many points as we can."
White Hart Lane will bid farewell to Jermain Defoe on Thursday with the striker, currently injured, about to complete his move to Toronto following 143 goals in two spells with Spurs.
Naughton added: "Defoe has been great for us while I have been here.
"He's been great to play with, just to give him the ball and let him do the business. He's been a great finisher, he still is, and a fans' favourite. He will be missed."