Howe failed to disclose before Saturday's 6-1 thrashing of Hull City which members of his squad had picked up problems while away with their respective nations.
The Cherries boss has now revealed who is in the treatment room, with the biggest concern being for midfielder Cook, who is set to see a specialist after suffering a "nasty" ankle injury while playing for the England Under-20s.
Howe told the Bournemouth Echo: “Lewis ran into a tackle and got his ankle caught in the turf and it was a really nasty-looking twist.
“We are waiting for him to see a specialist to see the exact time the injury will keep him out."
Max Gradel and Brad Smith also returned to the south coast with injuries, Smith sporting a protective boot at the weekend after damaging his foot playing for Australia.
There is no timescale on Smith's return but Howe is hopeful Gradel will not be out for too long with the hamstring injury he picked while with the Ivory Coast.