The emergence of Louis McCarthy-Scarsbrook has been a boost for Quins
The Rugby Football League has urged Harlequins to make more effort to attract crowds to the Twickenham Stoop.
Attendance figures will be one of the criteria used to determine clubs' suitability for the next round of Super League licences to be awarded in 2011.
Harlequins played to average home gates of just under 3,500 in 2009 and the RFL feels those figures are disappointing.
"I don't think there is an easy answer but they have got a bit of work to do," said RFL chairman Richard Lewis.
"It is a disappointment they haven't kicked on like we thought they would by moving to The Stoop.
"They are trying to work much more closely with the rugby league community game in London.
"Maybe there has got to be as much emphasis on getting people to come to the Super League matches as there is on getting them to actually play the sport.
"But I think Twickenham Stoop offers a great opportunity and Harlequins is a great brand.
"They have got a good team on the field and I do believe if they get it right off the field there is no reason why they can't get good crowds and be a full paying member of the Super League."
Although participation at amateur level has increased in recent years, that is not yet being reflected in crowds at Super League games at the Stoop, where the highest crowd in 2008 was 4,378 for the visit of champions Leeds in June.
The club have played at the ground for the last four seasons after the old London Broncos club were relaunched under the Harlequins guise. There has been criticism from some quarters within the game that Quins receive preferential treatment because of their location.
However, Lewis, speaking at his end-of-season media briefing, insisted Quins must work as hard as any other club to maintain their place in the elite competition.
He added: "I think it is understandable that some people are saying there should be as much pressure on them as other clubs in terms of pulling their weight in Super League."
In a statement, Harlequins said they were aware of the RFL's concerns and would be undertaking initiatives with the aim of improving the situation.
The statement read: "Harlequins have been working very hard with the RFL in all of the areas raised at yesterday's briefing.
"Together with the RFL, the club is developing its strategy for fixtures and the community game, amongst other key areas, with the aim of increasing attendances."