Orient goalkeeper Ben Alnwick has been signed off for unspecified medical reasons.

The stopper joined the O’s on deadline day last Friday after signing an 18-month contract from Charlton Athletic.

He had been due to make his second home debut for the club against Peterborough tomorrow but an Orient statement said: “A personal situation has arisen in the last few days which is preventing Ben from training or playing in matches.”

It has become a problem position for manager Russell Slade. First choice Jamie Jones is a long-term absentee with a back injury and Eldin Jakupovic was recalled by parent club Hull City after a successful loan spell.

Alnwick made his debut in last weekend’s defeat by Rotherham but again youngster Jake Larkins is left as the only fit, available senior goalkeeper at the club.

The emergency loan window opens tomorrow and the League One side are reportedly looking to sign Shwan Jalal on a one-month loan in time for Posh’s visit.