Stephen Kelly suffered a broken thumb and concussion towards the end of Tuesday's Carling Cup win at Burnley and has been ruled out of Saturday's clash at the Lane.
The Irish youngster had replaced injured Goran Bunjevcevic who was rushed to hospital for emergency surgery following Saturday's defeat against Charlton.
Goran - who had only played a couple of games at left-back himself - is now out for some considerable time after suffering internal bleeding into his shin, known medically as 'acute compartment syndrome'.
Thimothee Atouba (knee) is also out but thankfully Edman and Anthony Gardner returned to reserve team action at Watford on Wednesday night.
Edman played 60 minutes at Vicarage Road after a six-week stint on the sidelines following a head injury at Everton on October 2 while Anthony, who had also filled in at left-back but missed the last fortnight with a foot problem, played 75 minutes.
No decision has yet been made as to whether or not Edman will return to his left-back spot against Arsenal.
"There is something going on with the left full-back position because we've had injuries to Edman, Atouba, Gardner and Bunjevcevic so Kelly played and now he has a broken thumb and concussion," pointed out Head Coach Martin at this afternoon's pre-Arsenal press briefing.
"Erik played for the reserves at Watford but it was 60 minutes, not 90, and you cannot force things.
"We will talk this afternoon and in the morning with the medical staff and then we'll know what the situation is."
For the record, Edman, Gardner, Bunjevcevic, Kelly and Reto Ziegler have all played at left-back so far this season - Atouba would have as well, but was injured at Portsmouth.
The only other player on the missing list is Sean Davis, out but progressing well after knee surgery last week.
Our left-sided jinx has appears to have struck again as Martin Jol prepares for Saturday's derby against Arsenal.