"The board had concerns before they took over, but they've demonstrated they will listen," Gill told BBC Sport.
"Their business plan clearly allows for investment in the product - the team."
The Glazer family borrowed heavily to complete their estimated £800million buy-out of the club last June.
On Monday, the club announced a 12.3 per cent average rise in season ticket prices for next season, although a seat at United will still be less than at seven other Premier League grounds.
Gill said: "The debt within the club is serviceable and, what with stadium expansion and sponsorship deals, our income streams are in good shape."
Last week, United announced a £56million four-year shirt sponsorship deal with finance company AIG and next season Old Trafford's capacity will be 76,000, easily the biggest in the Premier League, even after completion of Arsenal's 60,000-seater Emirates Stadium.
However, Gill denied the club could consider renaming Old Trafford.
