Spain - Sevilla have to beat Manchester City in the Champions League on Tuesday to stand any chance of reaching the last 16, according to coach Unai Emery.
The La Liga side are third in Group D with three points, three behind City and four adrift of leaders Juventus.
"If we win tomorrow then City are catchable," Emery told reporters.
"If we draw we have a significant disadvantage, plus there's Juve there already with seven points.
"Therefore tomorrow is decisive. If we want to have optimistic hopes of reaching the last 16, winning is the only option we have," he was quoted as saying on the club website.
"It is a huge challenge, similar to that when we played Barcelona for the calibre of the opponent - the leaders of the Premier League, and it will take our best to overcome them."
Sevilla were moments away from claiming a point against City two weeks ago at the City of Manchester Stadium, only for Kevin de Bruyne to score in stoppage time to give the hosts a rather fortunate 2-1 victory.
They remained 11th after losing in La Liga for the fourth time this season on Saturday, a 2-1 reverse at Villarreal.
But Emery's players will take heart from their home form in Europe - the 2014 and reigning Europa League champions have won their last 10 European matches at their home ground.
"Tomorrow we are playing at the Sanchez Pizjuan and we have to continue with this consistency," Emery said.
Sevilla will be without injured top scorer Kevin Gameiro but hope midfielder Ever Banega is available after an ankle problem.