Speaking to the Daily Mail in his capacity as a Laureus Ambassador ahead of next week's awards ceremony in Madrid, the Porto president — who set a then-club record of 72 points during his time in charge of Spurs in 2012-13 — said the instability of ideas on the touchline is the defining factor in the club's decline.
"Eight managers in five years doesn't help because all of them are very, very different to one another, different methods, different way of selecting players, so this leads to instability as well."
He drew a direct contrast with how Porto have approached the same challenge. "What we have done at Porto, for example, when we found instability in the first year, we found stability right now in this year. We opted to renew our manager. Not only because of the results, but because of the relationship he has with the structure. Structure meaning scouting teams and youth-level teams in the way he promotes youth players coming through as well. So we believe in the stability going into the future."
"With Tottenham, you probably never had that in any of the cases because there is the pressure of results. But they have changed managers, they have changed the leading structures, they have changed also sports directors as well, from Franco Baldini to Fabio Paratici to the current sports director Johan Lange."
Tottenham are currently in the bottom three, without a Premier League win in the calendar year. Roberto De Zerbi, who took charge after Thomas Frank was sacked in February and interim manager Igor Tudor left by mutual consent, began his tenure with a 1-0 defeat away at Sunderland.
Villas-Boas was cautiously optimistic about De Zerbi's potential to change the club's fortunes but placed the burden squarely on the new head coach to deliver.
"De Zerbi has to deliver results. It's a long term contract anyway, so probably they have found out that those things that I mentioned here, De Zerbi will be able to deliver to them. And if eventually they go down, they can come back up because they have the infrastructure and the quality of the players and the resources to do it."