Indeed, the former Arsenal midfielder believes the north London side could have already secured the 22-year-old's services had they put a 'big bid' in at the start of the window - with Merson valuing Berahino at '£30 million at least.'
And the pundit highly doubts a sale will now happen in light of West Brom's public insistence that they will not do business.
Merson told the Star: "I don't think what Tottenham have offered is enough and I don't understand their tactics on this one.
"They need a striker but they've left it so late West Brom have turned around and said he's not going. You can tell that if Spurs had come in with a big bid at the start of the window they could have got him.
"But it might not happen now - and West Brom hold all the aces."
Merson's suggestion is consistent with an article written on HITC Sport on Thursday evening. In response, however, many have insisted West Brom chairman Jeremy Peace is simply playing hardball and will still sell Berahino to Tottenham - just for an elevated price.
Harry Redknapp certainly agreed with the idea that Peace is merely negotiating in his London Evening Standard column and the situation once again leaves us not knowing what exactly will happen until the transfer deadline passes.
West Brom may well hold onto the 22-year-old. Tottenham may well prise him away.