Di Maria played under Van Gaal at Manchester United and called him the "worst" coach of his career after his one-year stay in England.
"I don't like it that Angel said that, it's a pity," said Van Gaal.
"But sometimes a head coach has to take decisions that don't always end well."
Di Maria, who sat out the last-16 victory over Australia with a thigh problem, joined United from Real Madrid for £59.7m in 2014, but was sold to Paris St-Germain the following summer after starting just 20 Premier League games.
Speaking at a news conference on Thursday, the Dutch boss jokingly used his relationship with forward Memphis Depay, who also struggled under him at United, as an example of how relationships can alter over time.
"He (Di Maria) is one of the very few players who has ever said that, normally it's the other way round," said Van Gaal, before suggesting he and Depay were now close enough that he would happily give the forward a kiss.
The Netherlands expect to have a fully-fit squad to choose from as they face Argentina in a repeat of the 2014 World Cup semi-final, which was decided by a penalty shootout.
Head coach Van Gaal named an unchanged team in the last 16 with Depay starting back-to-back games for the first time since September.
Argentina's Di Maria has returned to training after missing the win over Australia because of a quadriceps issue.
Rodrigo de Paul will be assessed.
-- Courtesy of BBC Sport