The medic, a senior member of staff at Shrewsbury & Telford Hospital NHS Trust (Sath) who spoke on the condition of anonymity, said the move, which saw CEO Simon Wright announce the "difficult decision" to leave for another NHS job, seemed risky and could put the major Future Fit reorganisation of the hospitals in peril.
Their comments come amid confusion over Mr Wright's new role, with his position in the Nottingham and Nottinghamshire Integrated Care System not yet confirmed.
The timing of the decision to leave the trust, which manages Royal Shrewsbury and Princess Royal hospitals, has raised questions in some quarters, with Mr Wright staying on after it was placed in special measures following a critical CQC inspection last year.
Although the chief executive has proved a divisive figure with some, the Sath medic warned his departure could increase risks for patients.
The medic said: "Senior doctors are concerned at the manner in which Simon's exit happened. It comes at a very challenging time for the trust.
"We accept that he may not be universally loved but he delivered both Future Fit and the funding for it. Look around other big reconfigurations in the NHS. It can't be denied this is a big achievement.
"It seems crazy to lose the captain of the ship when he should be steering these difficult waters.
"No-one is denying the ongoing issues related to the CQC and maternity.
"It seems very risky to remove the CEO and puts Future Fit in peril. We believe that increases the risks for our patients. The chair has given cast iron assurance that Future Fit remains the trust's position and will be delivered."