Birmingham defender Jonathan Spector needs surgery on his fractured cheekbone and will miss the start of the season.
The United States international sustained the setback during a friendly against MK Dons last week and saw a specialist on Monday.
Spector was told surgery is required to mend the cheekbone, meaning Blues boss Lee Clark will begin the season without a player who signed a new two-year deal only this month.
Speaking about the incident earlier this week, Clark said: "It was absolutely ridiculous.
"It was so innocuous, it was 10 seconds from the end of the game as well, which is the frustrating thing."