The forward completed a £25 million move to Anfield on Friday after the Reds agreed to pay Newcastle’s substantial asking price.
He is the second high profile departure from the club this summer after Andros Townsend left to join Crystal Palace earlier in the transfer window.
His departure has been met with some dismay by fans, who are disappointed to see their top scorer from last season leave St James Park.
Benitez though, has insisted that the sale was in the best interests of the football club as a whole.
“In this case we have lost a very good player. I think though, that it was the best decision for him and for us,” he told the Chronicle.
“Gini was a good player and we allowed him to go to a Premier League club. But for us, the reality was that this was a good transfer but also we have kept a good team at the same time.”
It now remains to be seen whether Benitez will look to sign a replacement for Wijnaldum with the funds brought in from his sale.
His comments seem to suggest that will not be the case and he is happy with his squad as it is, but Wijnaldum will be a big loss for them.