Portsmouth administrator Trevor Birch says Michael Appleton's exit as manager was inevitable because of the circumstances he had to work under.
Appleton was named Blackpool boss on Wednesday after 12 months at Pompey.
In that time he saw the club's owner arrested, Pompey go into administration and later be relegated while also moving on his entire squad.
"It is disappointing but understandable given the situation we are in," Birch told BBC Radio Solent.
Appleton had been linked with a string of jobs over the past few weeks including Bolton and Blackburn while he was also interviewed twice at Burnley.
Portsmouth have been in administration since February and are currently in the process of a takeover by the Pompey Supporters' Trust, which has been vying with Balram Chainrai for the club.
The former West Brom coach was forced to sell all his senior squad in the summer and build a team of loanees, youth-team members and out-of-contract players.
It had been a difficult introduction to management for Appleton, but Birch believes he performed admirably in the circumstances.
"There has been a lot of interest in Michael over the past few weeks with the various managerial vacancies," added Birch.
"It is not altogether surprising that he has left but still disappointing and just another hurdle for us to get over.
"It was very difficult for Michael and not the job he signed up for so you have to have some sympathy there.
"In very difficult circumstances he did a good job. Just putting a team together for the new season was in itself a difficult challenge.
"To lose all the squad he initially inherited was obviously very difficult for him."
Pompey who are around £61m in debt received compensation for Appleton but reports Blackpool paid £200,000 for the 36-year-old are wide of the mark.
"There was compensation, it was helpful but it doesn't make any difference to the overall scheme of things as the numbers (the debt) are huge," added Birch.
Guy Whittingham will take charge of the team as caretaker manager on Saturday, but the club will not be able to appoint a permanent manager until they come out of administration and are taken over by the PST.
Names that have already been linked to the permanent role at Fratton Park include Whittingham, Andy Awford, Lee Bradbury and Stuart Gray.