Kenny Jackett said he had sympathy for sacked Sunderland manager Jack Ross.
But the Pompey boss admitted such departures came with the territory of managing in the modern game.
Ross lost his Black Cats job on Tuesday – 501 days after his appointment in May 2018.
He was sacked with Sunderland currently 6th in the League One table following a 2-0 defeat at the hands of Lincoln on Saturday.
The Scot went head to head with Jackett on six occasions during his time in charge at the Stadium of Light.
The honours were shared, with both teams winning two, drawing two and losing two each.
Pompey got the better of Sunderland in the Checkatrade Trophy final in April, while the Black Cats got one over their Fratton Park rivals in the play-offs at the end of last season.
Their latest match up came in August, when Sunderland recorded a 2-1 win on Wearside.
Jackett, who has also seen himself under pressure this season, admitted he didn’t get to know his counterpart that well during their meetings.
But he said Ross’ circumstances proved how difficult football management can be.
‘Jack Ross is not someone that I’ve spent a lot of time with,’ said Jackett.
‘He seems like a good guy.
‘But he’s not necessarily someone I would profess to know.
‘I would have sympathy with every manager and every person that loses their job.
‘We’ve played Sunderland a lot and they’re trying to get going again after a couple of successive relegations out of the Premier League.
‘It just shows it’s not easy for anybody.
‘For managers, generally, it is a privileged position.
‘Part of football is the changes.’