Mark Catlin believes Pompey did all they could to keep Paul Cook.
The Blues chief executive has lifted the lid on the sequence of events which led to Cook today joining Wigan.
Cook has moved to the DW Stadium on a three-year deal – 25 days after winning the League Two title.
Catlin thanked the 50-year-old for delivering success at Fratton Park.
He said: ‘This is football.
‘It’s a very transient business. Players come and go, managers come and go.
‘The rumours have been around for a while and we were approached by Wigan late on Friday.
‘Wigan were aware of the compensation payment due to release Paul and Leam, which they were prepared to meet. They then wanted to speak to him.
‘As a club, we did what we felt was correct. That wasn’t enough. Now we move on.
‘We did what we felt we could, it wasn’t enough and Paul has taken the choice to join Wigan.
‘We’ve run the club professionally and in a financially stable way for four years. That’s our intention moving forward.
‘All that matters to me is the well-being of this football club. That’s how I’ve worked for four years and will continue to work.
‘Paul came in and was employed specifically to do a job, which he has done.
‘While it is unfortunate he has left, we wish him well for the future.’
Kenny Jackett is an early contender to succeed Cook.
The likes of Gary Bowyer, Paul Tisdale, Darrell Clarke and Jimmy Floyd Hasselbaink are other names in the frame.
Catlin underlined the process of recruiting a new manager is under way.
He said: ‘In this business you are always working on a plan B scenario. We’ve been doing that.’