Hundreds of vacant posts could be axed at the Queen's Medical Centre and City Hospital as Nottingham University Hospitals Trust tries to claw back a £33m deficit.
Nottingham University Hospitals NHS Trust said there will be no redundancies, but vacant posts may not be filled or completely removed as a result.
The trust said no roles will be withdrawn that are critical to ensuring patient quality and safety but some clinical roles will be affected.
The trust, which runs Ropewalk House as well as the two hospitals, said "tough decisions will need to be made" to sort out the "£33m problem."
Other measures include looking at patients' length of stay in hospital and calling on commissioners for extra financial support.
The trust has until April to close the gap and said it will "give it every shot."
National 'bonus money' of around £30m could be at risk if the trust fails to meet its agreed financial targets, which includes hitting a surplus by April 2019.
This additional money would be invested into upgrading facilities, including wards and theatres at the hospitals.
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The trust employs around 15,000 people and receives just under £1bn in funding per year.
Hospital bosses said last winter contributed to the deficit, due to the cost of extra beds and catching up on around 800 cancelled operations.
Campaign group Keep Our NHS Public said this is a "new financial crisis" and that it was "unbelievable" that the government was not ploughing more money into the trust.
Mike Scott, spokesman for Keep our NHS Public (Nottinghamshire), said: "This is just unbelievable – the government refuses to provide enough money to run the most important public service and then penalises trusts when they can’t cope, so they’ll be even worse off the following year.
"A large majority of hospital trusts across the country are running at a deficit, so this isn’t about one trust’s inefficiency.
"The government has been pushing for extra clinics to be run in the evenings and at weekends, but hasn’t made any extra money available – where do they think it’s going to come from?
"And problems with recruitment across the board – many related to Brexit – mean there has been no reduction in the use of expensive agency staff.
"NHS workers tell us they can’t deliver quality patient care with these financial constraints and ask 'aren’t we just being set up to fail, so that private companies can come in and cherry-pick profitable services?' It certainly looks that way."
Rupert Egginton, NUH's chief financial officer, said: "Whilst the trust has an incredibly challenging 2018/19 financial plan, we remain focused on doing all we can to get the best possible financial results by year-end.
"Our financial position has deteriorated since quarter two as we have begun to see the true effects of last winter, including the cost of cancelled operations and associated catch-up activity and escalation beds that remain open as a result of the demand on our emergency services which is significantly above plan year-to-date.
"The cost of the coming winter, including opening 116 additional seasonal beds, has added a further cost pressure.
"Reaching our agreed year-end surplus position is dependent on the trust meeting its £41m savings target, receiving national monies linked to our financial and operational performance and securing additional financial support.
"We have developed a financial recovery plan to close the gap, which includes applying strengthened controls to reduce all spend in the remainder of the year."
