Benfica president Rui Costa says it was nigh impossible to keep hold of Darwin Nunez over the summer.
The Uruguay striker was sold to Liverpool for €100m before the start of the season.
Rui Costa said: "We are talking about one of the highest transfers on the market, and we are getting out of the pandemic situation that has stopped the market.
"There wern't the conditions to continue.
"It was practically impossible to keep Darwin, either for the proposals or for what he was going to earn."