Gary Smith says the decision to sack him as Stevenage boss was "strange" with the club having seemingly retained its League One status.
Boro chairman Phil Wallace last week after a run of 14 losses in 18 games.
"I think the timing is the thing that sits a little strangely," Smith told BBC Late Kick Off East.
"To know that we've confirmed our League One status and to be out of a job is of course upsetting."
Stevenage's early season form, which put them in the top six as recently as December, meant their string of poor results only pulled then down to mid-table.
at Broadhall Way, after defender Mark Roberts took temporary charge in
The prospect of relegation remains highly unlikely though, with the Hertfordshire side 11 points clear of the drop zone.
And Smith, 44, said survival had been his remit from the beginning.
"The chairman's philosophy, which has been a good one, was to make sure the stability in League One was there," said the former Colorado Rapids manager.
"I think at this point we can safely say we've achieved that. But of course there were concerns in his mind about the way things were going.
"We have been on a difficult run and I think expectation from the start of the season, after being in the top six for a good period, has maybe played into it. But I was surprised. There were many emotions."