As things stand, Spurs are set to see three senior stars hit free agency in the summer of 2020.
No extensions have been agreed with a Danish playmaker and two Belgian defenders.
That trio have offered no indication that they will be committing to fresh terms, with Eriksen having already stated that he is open to taking on a new challenge.
O’Hara is surprised that Spurs chairman Daniel Levy has allowed such a situation to arise, with failings at the Tottenham Hotspur Stadium mirroring those which have become a cause for concern across north London at Emirates Stadium in recent times.
“I think that is the biggest problem Spurs have got,” O’Hara told talkSPORT.
“You’ve got Vertonghen, Alderweireld and Eriksen who are going to leave; they are going to go for nothing and might even go in January if Tottenham feel they need to get rid of them and make some money.
“That is a big problem.
“I’m so surprised that we’ve allowed this to happen because, truthfully, this doesn’t happen at Tottenham.
“Knowing Daniel and how he works, he will always give an extension and add another extension two years down the line so you’ve always got these players, because they are assets to the football club.
“You are losing three huge assets for your football club who could truthfully fetch you, in the right market, £100million.
“I gave Arsenal a load of stick for this when they let Ramsey go and let others go for nothing, thinking how can they let these players’ contracts run out?
“But now Tottenham are about to let three of their biggest players go for nothing. It’s crazy!
“We sold [Kieran] Trippier and didn’t replace him and now we’re going to lose our two centre-halves as well so we’ll need a whole new back four!”
Spurs did, after two windows of no activity, dip back into the transfer market over the summer.
They did not, however, bring in any new centre-halves or players of a similar ilk to Eriksen that could fill the playmaking void that his departure would create.
Mauricio Pochettino has already conceded that he will be forced to add again in January, with Tottenham needing to right the wrongs of a slow start to the season and plan for possible departures at the end of the current campaign.