Middlesbrough defender Emanuel Pogatetz will be out for around six weeks after surgery on a fractured cheekbone.
The former skipper made his first appearance of the season on Saturday, with new boss Gordon Strachan naming him at left-back for the visit of Plymouth.
However the Austrian ace’s comeback was halted by a clash of heads with Argyle defender Shane Lowry.
A Boro spokesman revealed that Emanuel Pogatetz has fractured his left cheekbone and that it is a recurrence of the injury the player suffered playing against Basle in the UEFA Cup in March 2006.
Pogatetz might be able to return earlier if he gets clearance to wear a mask.