The winger joined Mauricio Pochettino's team on deadline day for £25 million after Spurs made a last-minute offer for the rising star.
Speaking to the club's official website (h/t Darren Wells of the Mirror), Fulham vice-chairman Tony Khan explained Spurs did not follow up their initial interest in the player over the summer and only decided to match Fulham's valuation late in the day.
"We heard from them [Spurs] for the first time two weeks before the close of the window.
"We had been making all our deals under the assumption that Ryan could wind the contract down and they were not going to offer us anything. I was totally prepared for that.
"We had got three of our top four targets on loan but there was still a lot of uncertainty about what we could do in the rest of the window after we got Ivan Cavaleiro, Anthony Knockaert and Harry Arter.
"It turned out we were not able to buy any players because this transaction had been held up. And when I finally got an offer it was so ridiculously low that I had to make it super clear that we were not going to take a penny less than our asking price, which is exactly what we got."
Khan said he would have been content for Sessegnon to play for them in the EFL Championship and wind down his deal if Spurs failed to match their valuation. The player had 12 months remaining on his contract with the Cottagers.
Sessegnon said he can't wait to begin the next chapter of his career:
Per the club's website, Khan said the two teams were still apart on striking a deal 24 hours before the transfer window closed. The vice-chairman insisted Fulham had no opportunity to spend on a replacement until Spurs agreed to pay the fee on the afternoon of deadline day, with the window shutting at 5 p.m. BST.
Despite Fulham's complaints, Spurs have signed a wonderful player who could go on to be one of the best in the Premier League. Sessegnon began life as a left-back, but he's a talent who knows how to exploit opposition defenders. He is a natural goalscorer and should become a productive forward.
The player's fee is small in terms of current top-flight transfers, and the teenager will be knocking on the door of Pochettino's first team in the weeks ahead. Sessegnon is destined to become a star for England, and the Tottenham Hotspur Stadium is the perfect stage for him to progress to the next level.