Sevilla defender Nicolas Pareja is facing up to seven months on the sidelines after tearing the anterior cruciate ligaments in his right knee during the UEFA Europa League clash at Zenit.
The Argentine centre-back was withdrawn in the first half of Thursday's 2-2 draw against the Russian Premier League leaders, which saw the Spanish side progress 4-3 on aggregate, after landing awkwardly.
Sevilla revealed on Friday that the 31-year-old requires surgery and is not expected to return until late this year.
Pareja's absence is a blow for Unai Emery's side as they battle to secure a Champions League place and win the Europa League for a second successive year.
Meanwhile, Vitolo is also set to miss Sunday's trip to Rayo Vallecano due to a hamstring twinge and could sit out the midweek encounter with Eibar, but the winger is expected to return against Real Madrid a week on Saturday.
Sevilla will face Fiorentina in the semi-finals of the Europa League.
