Morrison, who has been a vocal supporter of keeping the club in the capital, believed there were a range of reasons for the low crowds this summer.
"I think the first thing is there's a degree of hangover from the Rugby World Cup because an awful lot of people spent an awful lot of money on tickets, going as an experience," Morrison said.
"I have no fears at all in terms of losing the Phoenix. I know all the businessmen and they're very staunch Wellingtonians, but if it's about cashflow and trying to balance the budget it's fair enough. So the challenge is out there.
"I would hope on Sunday we'll get a really good turnout but I think Gareth's got a really good idea. It's good to provoke Wellingtonians, saying 'get off your backside, we all busted our gut to try and keep them, let's do the job'. So that's the challenge that's out there and I accept it as well."
Yellow Fever member Guy Smith said a key factor in the crowd numbers being down during the past month was the holiday period and he echoed Morrison's thoughts that Sunday's home game against Melbourne Heart was vital to prove they could pull a big turnout.
"I think the next home game's going to be the acid test this weekend," Smith said. "People are back, the team's going well, the team's winning, so we would hope for a crowd of 8000-plus."
More than 20,000 fans turned up Eden Park for a game against Adelaide United in November, although only 4600 attended the club's December fixture against the Brisbane Roar in Dunedin.
The time of year did Dunedin no favours with students out of town and the game was also played on a Wednesday at a time during the season when the Phoenix were struggling on the park.
Despite the low number for the Brisbane game, Forsyth Barr Stadium chief executive David Davies said they would welcome the Phoenix back with open arms.
"We were very modest in what we expected to get in but 5000 is pretty good going considering there was no season ticket holder base, which you would expect if they were playing in Wellington. We will be very pleased to host the Wellington Phoenix again.
"The event down here pre-Christmas made money for us. Some of the bigger names in the national press have said it was a failure. We made money. It was a community event."
The Phoenix have also played "home" games in Palmerston North and Christchurch in the past.