It was confirmed on Saturday that the 22-year-old would sit out his side's upcoming semi-final with Germany, and possibly the final, with a fractured vertebra.
"I'm incredibly sorry for Neymar. He's an amazing footballer and it's really bitter and hugely unfortunate that he's going to miss out - for him, for his team and for the whole nation," Low is quoted as saying by FIFA.com.
"I hope he recovers and is playing again as quickly as possible and that he can deal with this setback positively."
Germany and Brazil meet in the semi-finals of the World Cup in Belo Horizonte on Tuesday night.