Lotte Wubben-Moy and Nikita Parris have been called up to the England squad for the October international camp following injuries to Leah Williamson and Lucy Parker.
Williamson - who captained England to Euro 2022 glory this summer - will undergo further assessment on an injury sustained in training.
Parker - who received her first senior England call up last week - sustained the injury during West Ham's Continental Cup penalty shootout victory over London City Lionesses on Sunday. The defender will return to West Ham to continue her rehabilitation.
England face World Champions the USWNT at a sold out Wembley on Friday 7 October, before taking on the Czech Republic in Brighton on Tuesday 11 October.
Williamson and Parker's injuries follow Monday's news that Manchester United striker Alessia Russo has been forced to withdraw from the England squad due to a 'small injury'.
Wubben-Moy and Parris were two of four members of England's Euro 2022-winning squad not selected by Sarina Wiegman for the October camp, with the pair yet to start a WSL match for their respective clubs.
Parris did make her maiden start for Manchester United in the Continental Cup on Saturday, and marked the occasion with a stunning individual goal.