The Everton defender had already missed the Toffees’ 1-1 Premier League draw with Liverpool at Goodison Park, and it was confirmed on Tuesday that the 21-year-old will sit out Friday’s clash with Estonia.
Joining England captain Rooney on the sidelines at St George’s Park yesterday were Danny Ings and Jonjo Shelvey.
With the aforementioned trio a doubt for the two matches, Walker’s teammate Andros Townsend has also been gifted with a late comeback.
“They will be monitored ahead of Friday’s meeting with the Estonians at Wembley…”
Former Sheffield United defender Walker, who has picked up 11 caps, hasn’t played for England since featuring in the friendly against Italy in March.
England are already guaranteed top spot in Group E and will finish the qualifying competition with a 100 percent record if they win their remaining two games.
Everton centre-half John Stones is set to be released by England on medical grounds after linking up with Roy Hodgson’s squad.
Hodgson’s men will then fly to Vilnius to take on Lithuania three days later.