Liverpool striker Andriy Voronin faces six weeks on the sidelines following confirmation he needs an ankle operation to repair ligament damage.
The Ukrainian suffered the injury in training early this week and the problem is worse than first thought.
The 28-year-old will certainly miss the first leg of Liverpool's Champions League tie with Inter Milan next month.
Voronin, who signed from Bayer Leverkusen in July, has scored three goals in 11 Liverpool appearances.