The visiting R's trailed 2-0 at the break at the Liberty Stadium, before eventually going on to lose the encounter 4-1.
Reflecting on the performance, Spaniard Granero has admitted that the players did exactly what they were told not to do by manager Harry Redknapp.
"We respected them too much in the beginning, which is exactly what the manager told us not to do," Granero told the club's official website. "We had a bad first half against a team who has some of the best play in the Premier League. They kept the ball and we struggled to get it back. They scored two early goals as well which made it harder for us."
The result has left QPR seven points from safety.