Natalia is 30, but these are nagging injuries. We forget she’s been with the national team since 2006 (albeit not on 2008 Olympics roster). Many times as a sub, before moving into the starting lineup.
When she’s part of the lineup Brazil is a better team, without her, it is not as stable. Gabi is a great player, and has carried much of the team this year, but that extra support from Natalia takes some the pressure off of her.