Phil Jagielka missed training on Thursday with a fractured toe as England stepped up their preparation for the friendly with Spain on Saturday.
The Everton defender will now be monitored by the Three Lions' medical staff over the next 24 hours before a decision is made on whether to play him.
Jagielka, however, would have to be able to train on Friday to have any hope of facing the World and European champions.
The former Sheffield United man incurred the injury against Fulham on October 23rd but has continued to play with the aid of pain-killing injections.
England's physios have been in close contact with their counterparts at Everton and both parties spoke again on Thursday morning.
Jagielka's absence from training was the only concern for Fabio Capello who put the rest of the squad members through their paces at Arsenal's London Colney training headquarters.
It is very much an experimental squad that has been named by Capello with 11 players having won six caps or less.
Another central issue for the Italian taskmaster remains who will captain the team in the absence of John Terry after he opted to rest his skipper for this glamour friendly.