United States women's internationals Megan Rapinoe and Alex Morgan have become the latest players to join Common Goal.
The U.S. stars have pledged, along with Bayern Munich defender Hummels and Manchester United midfielder Juan Mata, to donate one percent of their salaries to the charity on Thursday.
Rapinoe highlighted the importance of women joining, saying: "Common Goal is intended as an inclusive initiative, and myself and Alex felt it was important that women's football was represented from the outset.
"We're really looking forward to building the movement with Juan and Mats from here. The sky is the limit at this stage.