Chelsea had an agreement in place with Leeds to sign the Brazilian and were expected to complete the deal to sign him from the Whites.
But Raphinha waited for Barcelona, who took their time to arrange the funds, and they finally agreed on a fee to sign from Leeds.
But Radrizzani regrets the fact that Raphinha did not end up at Chelsea as he had a deal in place with the Blues.
The Leeds owner admitted that he felt guilty when he had to go back on the word he had given to his Chelsea counterpart Todd Boehly, but stressed that he had no choice in that matter.
He insisted that selling Raphinha was important for Leeds in order to bring in the players they wanted.
Radrizzani told The Athletic: “For me, the deal was done with Chelsea.
“When I have a deal, my word is my word and I felt ashamed to go back to Todd Boehly, the owner of Chelsea, and change the position.
“It was really, for me, disrespectful and was not the right thing to do but I didn’t have a choice.
“If I decided I wouldn’t sell the player, I would have preferred that, but I didn’t have a choice.
“For us, it was more important to buy six players than keep Raphinha.”
Barcelona are yet to find out whether they will be able to register Raphinha in time for him to play in the opening game of the season later this month.
