Only four players, two of them first-teamers, were released.
Following a final team meeting of the season at Victoria Park yesterday, when Cooper told his players what is expected of them during the summer and when they return for pre-season training in the first week of July, Pools announced contract options had been taken up on nine players.
They are Jack Compton, Michael Duckworth, Scott Flinders, Jon Franks, Darren Holden, Luke James, Andy Rafferty, Jordan Richards and Josh Rowbotham.
Striker Marlon Harewood agreed an 18-month deal when signed in January and is under contract for next season, while Bradley Walker’s deal takes him through next season.
The club is in talks with a number of other players with Sam Collins and Neil Austin expected to sign new deals, and discussions on-going with James Poole, Lewis Hawkins and Antony Sweeney.
Club captain Sweeney has not started a game since the December 14 draw at Cheltenham and has only played 106 minutes of football since then, with his season ended by injury in home defeat to Mansfield on March 25.
Monkhouse signed for Pools in November 2006 and made 331 appearances, to put him 11th in the all-time appearance record. He scored 52 goals and was top scorer in both 2009/10 and 2012/13.
He suffered a recurrence of a recent hamstring injury in the penultimate game at Plymouth and was absent for the final game last weekend.
Neither he nor Walton were at Victoria Park for the Exeter defeat, after earlier learning their fate.
Walton signed on a free transfer from Plymouth in July 2012, and made 83 appearances for Pools, scoring four penalties.
And Cooper has warned his squad that finishing 19th in League Two, as they have done this season, is far from acceptable.
Following his first season as a manager, Cooper said: “There’s been highs, lows, this season – but not good enough.
This club has to realise that whatever has gone on in the past, we consider this as bottoming out.
“I accept I walked into the club with my eyes open and with a list of players that had already been signed and with very little room for manoeuvre with Financial Fair Play.
“It’s not revolution, it’s evolution.
“But some things will change this summer and the longer I’m here things will change longer-term.
“Our sights are set in a way that we put ourselves in a place to be successful. It’s the biggest summer of the players’ lives.
“Unfortunately for them, I know what it takes to play at the highest level.
“If they want to play at being a footballer then they can’t be here.
“People might say that over the weeks and months certain people have tried to make their feelings clear to me, well I am doing my damnest to try and be successful next year. If I’m not then I won’t be here.
“But I cannot allow the players to play at being a professional footballer. If you aren’t serious about it, you should not be here.’’ Pools will head to Spain and a training camp at the La Cala Resort in early July, after visiting both Holland and Norway over the last 14 years.
They won’t be playing any games in Spain.
Pools ended their season on a low with a poor home defeat against Exeter and Cooper insisted: “It (Exeter performance) means I have to look at things even deeper than I have been – I cannot tell you how disappointed I am.
“We have to accept that in order to improve we cannot afford any more days than this.
“I will still work with the young players and try and add better players around them to make them better. I have to say the lads we have had on loan from their respective clubs have done themselves and their clubs a great deal of credit.
“Now we have to make our players better and more hungry.
This club has stuttered and stalled in recent years and I have to improve it.
“Next season cannot be the same as this one – if we finish 19th I won’t be here. I won’t accept any mediocrity.’’