The Light Blues board last week revealed they will launch a share issue for existing shareholders to raise cash.
But chief executive Wallace knows much more is needed for Rangers to compete in the Premiership from next season.
He said: "I outlined in the April business review that the club requires investment over a rolling future period to develop and grow.
"This position remains unchanged today.
"The club announced that it will seek to raise £4million from existing shareholders to provide a measure of financial support in the current year. The required authority for this share issue is already in place.
"It was also announced that the club will seek shareholder approval at the Annual General Meeting later in the year for further issues of new shares, to provide the financial capability needed to develop the club for the future.
"This is all part of a long-term strategy to rebuild the club."
A quick-fix cash injection has become increasingly vital in recent weeks after a big slump in season ticket sales for the Championship campaign.
Thousands of fans have refused to pay in protest at the under-fire Ibrox directors as tensions between supporters and the board have escalated.
Wallace said: "The club understands and respects the decision of fans to make the choice they feel is right and we hope that those who have not purchased season tickets will continue to support their team on a match-by-match basis to allow us to continue to develop and grow the club for the future."