Pardew suffered a blow in January when star midfielder Yohan Cabaye departed to join Paris St Germain.
Since then, United's potential challenge for a place in Europe next season has faltered as injuries, suspension and the impact of the Frenchman's departure took their toll.
Ahead of this weekend's clash with Manchester United, Pardew admitted that this summer was always likely to be one of change for his squad.
"I thought this summer would be a summer of that because the age of our players, the quality we have got, you were guessing that one or two might go," he said.
"And with the players that we have with a year left (on their existing contracts) and those who are up, it was always a big job this summer.
"Most summers are (transitional) at Newcastle, but this one is perhaps more important than most.
"But we have got a transfer kitty that should work for us if we get the right players."
Currently, United have two strikers on loan in the shape of Loic Remy and Luuk de Jong, with the former likely to attract plenty of interest from clubs following a successful season and the latter having failed yet to demonstrate why he would represent a good long-term signing.
In addition, last year's captain Fabricio Coloccini has expressed his desire to return to Argentina.
And there are question marks too over the futures of Hatem Ben Arfa, Sylvain Marveaux, Papiss Cisse and Sammy Ameobi, while Dan Gosling and Shola Ameobi are out of contract at the end of the season and Ryan Taylor and Jonas Gutierrez are among those who will have only 12 months remaining on their deals.
France international Cabaye joined PSG for a large fee but had to settle for a late substitute appearance in the Champions League quarter-final first leg against Chelsea this week.
This has prompted Pardew to warn others looking to leave Newcastle that the grass is not always greener elsewhere.
"Yohan has gone there to win trophies - you could argue that they could be in the semi-finals next week, so I am not going to argue with his decision," added Pardew, who has also seen both Andy Carroll and Demba Ba leave the club in recent seasons.
"It is his decision and players have to live and die by those.
"But most of the players who have left this club in the time I have been here haven't gone on to better themselves, really, and that's an indication of the job we do here, in my opinion, on the coaching pitch and the platform they have at this great club."