Current balance early on is often very positive, because some revenues are paid "up front", namely season tickets and media revenues.
But as you play out the season, you pay more in salaries than you bring in from remaining ticket sales and merchandising, so that number will fall over time, often to around what the projected value ends up being.
Now, it won't always. For example, if you sell more tickets than expected, that can gain money. Or if you make the playoffs, that can be another big chunk of revenue too.
If you don't want to rely on that, then you can cut expenses. Trading away high cost players is one, or sometimes you can reduce your scouting, development, or drafting budgets too.
Or don't, and hope your generous owner covers the shortfalls and doesn't get mad
