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.”
England interim boss Hege Riise said there is “concern” about her team’s friendly against France on 9 April after a coronavirus outbreak in the Lyon squad.
Several Lyon players also represent their national team, but the whole squad have now been placed in quarantine and their Champions League tie against Paris St-Germain has been postponed.
There are further doubts about England’s friendly in Caen because France could also be placed on the UK government’s ‘red list’ for travel.
It is understood talks are continuing on Tuesday.
Asked about potential cases among France players, Riise said: “That will be a concern. We still don’t know.
“We don’t want to risk anything, but our plan is to go to France and play, and we haven’t heard any different.”
Lyon forward Nikita Parris was also left out of the England squad for one of two friendlies that the Lionesses will play. The other is against Canada at Stoke City on 13 April.
But Riise said Parris could join the camp “for the last part” and confirmed the squad would only travel to France the day before the match.
Asked why Parris could not play against France in Caen, Riise added: “I don’t know all the details in there, so I need to hold back on my answer.”
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
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