Middlesbrough officials may have to wait until the end of the week to find out the extent of German defender Robert Huth's injury.
After a prolonged run in the side this season, Huth had to sit out Saturday's win at Wigan after picking up an ankle knock in midweek and Southgate says they are still waiting to find out the result of scans.
"Robert has a problem with his ankle ligaments but we don't yet know the full extent of the injury," Southgate told the Gazette.
"The area is very swollen and it's difficult to give an accurate assessment at this stage. However, we should have a clearer picture by the end of the week."