Confirmed: Ireland international Darron Gibson secures move to Sunderland
As the Dutch full-back completed a move to Crystal Palace, which could eventually see the Black Cats collect £14million, Everton duo Bryan Oviedo and Darron Gibson were on Wearside to join former Toffees team-mates Joleon Lescott, Victor Anichebe and Steven Pienaar, who had earlier answered Moyes' call to arms.
Costa Rica international full-back Oviedo has signed a three-and-a-half-year deal and Republic of Ireland midfielder Gibson has penned a contract lasting for 18 months.
Van Aanholt's decision to hand in a transfer request gave Moyes a decision to make and, with funds limited and the club's wage ceiling perilously close, he rather than chairman Ellis Short decided to sell.
Moyes said: "I thought it was a good deal, but I have got to say, it was solely my decision. It wasn't Ellis' decision, it was my decision to sell Patrick, so if anybody thinks it was because Ellis was wanting money, it was far from that.
"There are several reasons for it, but one of the main ones was that I felt that it would allow me to bring in other players. Because of the level of the wages, the sale meant that I had opened up the ceiling, which allowed me to maybe get some players in."
Van Aanholt's determination to head for Selhurst Park meant a change of focus for Sunderland, who had not initially included a left-back on their shopping list.
Moyes admitted: "I have known for a while what Pat's thoughts were, but it was always going to be difficult getting a replacement, that was the thing.
"We had an idea of some players which we might be looking at if we could do anything in January and one of them wasn't necessarily a left-back, so when this came in it turned it up a wee bit."
The cash raised by Van Aanholt's departure allowed Moyes to return to his former club and snap up direct replacement Oviedo and experienced, but injury-plagued, midfielder Gibson.
Oviedo, 26, made just 68 senior appearances during his four and a half years on Merseyside, while 29-year-old Gibson managed one more in his five years.
Moyes, whose side faces high-flying Tottenham in the Premier League on Tuesday evening, said: "Every player who is coming into Sunderland is a bit of a gamble. I don't think we could get an absolute nailed-on player, I don't think that's the case."
The Scot is hoping to land a striker during the final few hours of the transfer window, with the club understood to have had a series of bids for Leicester's Leonardo Ulloa rejected with the champions seemingly unwilling to do business with them.
But asked if he felt the transfer window had gone as well as it could have in the circumstances, Moyes replied: "I always like to think I could do much better, but there have been players who we have wanted and we have not been able to get or not been able to attract."