QPR have started the campaign without victory in any of their 12 Premier League matches and they prop up the table with just four points.
Such poor form has seen manager Hughes' position come under increasing scrutiny and Nelsen knows his players have to react, starting this weekend at Manchester United.
"When the pressure is on, players have to take responsibility," he told the club's official website.
"It doesn't matter who you're playing, the Premier League is just unforgiving. You've got to earn your right to play and win.
"You've got to be strong mentally and have the confidence to do something in the game at both ends of the park."