Capello wants to know that Barry can return imminently to training from his ankle injury and, after giving him as long as possible to prove his fitness, today is finally D-Day.
The Telegraph says Barry will be tested by the Football Association's medical team, led by Dr Ian Beasley, who will examine his MRI scans to assess how his damaged ligaments are progressing. Although Capello has been reassured that Barry and the Manchester City doctors believe he will make it - he is now able to run on a specially-balanced treadmill - he wants to have first-hand proof.
Capello, who has until 11pm tonight to submit his squad to Fifa, will have a final conversation with his trusted right-hand man Franco Baldini after assessing Barry's fitness. He will then telephone the seven players who have not made the final 23-man squad before an announcement is made on the FA website.