England captain Terry remains doubtful

(CNN) -- England captain John Terry remains a doubt for Saturday's World Cup qualifier against Kazakhstan at Wembley.

The Chelsea central defender has been troubled by a back problem and while he was able to play some part in training on Wednesday after missing Tuesday's session, he did not complete it all.

England's medical staff will continue to assess Terry's fitness but Wes Brown, Matthew Upson and Joleon Lescott could all come into contention as a replacement.

Coach Fabio Capello also has an instant replacement as captain, having named Rio Ferdinand as his vice-captain in August.

Terry's reluctance to miss any game could still see him involved on Saturday, but with little training behind him, Capello may opt to keep him fresh for next Wednesday's trip to Belarus.

Capello would certainly hope to have Terry involved in an intended practice match on Thursday, in which it is thought Steven Gerrard and Frank Lampard will attempt to show they can play together in central midfield.

Emile Heskey is expected to be involved after sitting out training on Wednesday with a back injury, which is also the problem Jermaine Jenas was nursing, although the Tottenham man should also resume his battle to impress Capello on Thursday.