Spurs have targeted a deal for Welsh international Rodon during the latter stages of the window, but were under no pressure to seal a deal before the close of the international market last week.
The extended domestic window – which closes at 5pm BST on Friday (October 16) – gave Tottenham more time to reach an agreement, with the two clubs initially miles apart when it came to an acceptable fee for one of the Championship’s top young talents.
Talks have been ongoing, though Standard Sport understands that, as of last week, Spurs and Swansea – who originally valued Rodon at £7million and £18m respectively – were still some way off finding a compromise.
Cooper was inevitably asked about transfers in his latest press conference before Swansea return to second-tier action following the international break with a home fixture against Huddersfield Town at the Liberty Stadium on Saturday.
“What I would say about Joe or any other of our assets – and Joe is right up there as one of our biggest – it’s really important that if we do end up having to sell then we get something to show for it,” Cooper said.
“We shouldn’t be selling on the cheap. The precedent has been set this year.”
Cooper specifically referenced the recent transfer involving Ben Godfrey, with Premier League pacesetters Everton paying Championship Norwich City £25m plus add-ons to take the defender – who, at 22, is the same age as seven-cap Wales international Rodon – to Goodison Park.
“The player [Godfrey] is not a full international,” he added. “Joe is and you have seen how well he played for Wales.
“If that’s what the going rate is and that’s the numbers getting bandied around, whether I agree or not, that’s what it is.
“If we do lose an asset then our supporters will want to see some reinvestment and some good players coming in.”