The 29-year-old has scored 29 of Palace's 67 goals in the Championship so far, which is a large reason why the club have found themselves in contention for an automatic promotion berth.
However, both Murray and Palace are without a goal in their last three outings and Holloway has conceded that his players need to work hard in order to rediscover their clinical touch.
"We've always been short of goals if Glenn hasn't scored and that's the truth of it," Holloway told reporters. "When I first arrived at this club I saw players step up to the plate. We had three penalties in one game, two in the next and great free kicks being whizzed in.
"It isn't going that way at the moment, so what we have to do is all stick together and keep working hard."
Palace are fourth in the Championship standings with six matches left to play.