Things have not gone to plan for the west Londoners this season, with a summer of hope abruptly ended by a winless start to the season.
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."
That mental strength was far from evident last weekend as QPR fell to an embarrassing 3-1 home defeat to fellow strugglers Southampton.
The players' perceived lack of effort against Saints saw the Loftus Road faithful turn on their players, chanting 'you're only here for the money' and 'Ryan Nelsen, he plays on his own'.
"I thought we were poor in both boxes to be honest," Nelsen said of the performance.
"We were all extremely disappointed. You get punished no matter who you're playing in this league.
"The players have to hold complete responsibility for last weekend. When it mattered most, we just didn't stand up.
"You've got to defend and attack the ball and we just didn't get on the end of anything.
"Every game from now until the end of the season is a 'stand up and be counted' game.
"Every player's got to hold their hands up and do everything they can for this club to get out of where we are."