Head Coach Martin revealed that an Achilles injury forced the Swedish full-back off at half-time in last night's 1-0 defeat at Aston Villa.
"Yes, it is an Achilles problem but I can't tell you much more until the morning," said Martin at Villa Park.
"But at least Thimothee Atouba showed me that he could play at left-back."
Thimothee - his first start since a knee injury last month - reverted back to the position following Erik's injury with Reto Ziegler coming on at half-time and playing left midfield.
Martin Jol faces an anxious wait for medical reports this morning on the extent of Erik Edman's injury.