England will be without captain Steph Houghton for April’s friendlies against France and Canada.
The defender was not named in Hege Riise’s 24-player squad after picking up an Achilles injury while playing for Manchester City.
Forward Nikita Parris is also unable to join after a number of positive coronavirus cases at her club Lyon.
The Football Association says the situation is being “regularly assessed”.
England play France in Caen on 9 April before hosting Canada at the Bet365 Stadium in Stoke on 13 April.
Both matches are live on BBC Four, the BBC iPlayer and BBC Sport website.
Experienced goalkeepers Carly Telford and Karen Bardsley have been named in the squad, which will meet at St George’s Park on 4 April.
Uncapped defender Niamh Charles of Chelsea and Manchester United’s Millie Turner have also been included.
“We have such an exciting group of players; many have enormous major tournament experience and others have proven themselves capable of competing for England at the highest level,” Riise said.
“This international window will really test our squad against some of the best in the world, which is crucial as we move closer to the Tokyo Olympics.”
Full England squad
Goalkeepers: Karen Bardsley, Sandy MacIver, Ellie Roebuck, Carly Telford
Defenders: Millie Bright, Lucy Bronze, Niamh Charles, Rachel Daly, Alex Greenwood, Demi Stokes, Millie Turner, Leah Williamson, Lotte Wubben-Moy
Midfielders: Fran Kirby, Jordan Nobbs, Jill Scott, Georgia Stanway, Keira Walsh
Forwards: Bethany England, Lauren Hemp, Chloe Kelly, Beth Mead, Ella Toone, Ellen White