Valencia, Aug 18 (IANS): Spanish football club Valencia face one of their most important nights in recent history when they entertain French side Monaco in the first leg of their Champions League qualifying round on Wednesday.

Valencia earned the right to battle for a place in Europe's top competition thanks to their fourth place finish in the La Liga last season, reports Xinhua.

The side, coached by Nuno Espiritu Santo, now have to make good their efforts over two legs of the qualifier in which any mistake could undo all of last season's good work.

It has been a difficult summer at Valencia with the sale of the club to Singapore-based businessman Peter Lim, which has upset some sections of the supporters who made their displeasure known during Valencia's 0-3 home loss to Italian side AS Roma at a practice match just over a week ago.

Preparations for Wednesday's game have not been helped by the ongoing transfer saga involving central defender Nicolas Otamendi, who looks certain to join English outfit Manchester City.

Otamendi's departure will leave a hole in the defence after his excellent displays next season, but his defensive partner Shkodran Mustafi has highlighted the need for the rest of the players to remain united.

The match will see the competitive debut of Australian international goalkeeper Matt Ryan, while striker Paco Alcacer will hope to start the season in the rich form which saw him debut for Spain a year ago.

Monaco will be without influential midfielder Joao Moutinho, who has an ankle injury, while defdender Layvin Kurzawa is a major doubt for the French side.

They also have a fitness advantage over Valencia given that the French league has already played two games, while in Spain competition doesn't start until this coming weekend.

That should serve as a warning to Valencia that they have a lot of work to do, but with the atmosphere already tense at the club anything other than a win on Wednesday will only serve to ramp up the pressure on coach Nuno.