Madrid, April 9 (IANS): Spanish clubs Sevilla and Valencia both have tough work to do if they are to qualify for the semi-finals of the Europa League football Thursday night.

Although they are at home for the return legs of their quarterfinal ties, both have to overturn deficit after losing their opening games and will need the support of their fans to carry them through, reports Xinhua.

Sevilla have the easiest of the two tasks as they look to make up a 0-1 deficit to Porto.

Although the team which is currently third in the Portuguese league knows that an away goal in Sevilla's Sanchez Pizjuan Stadium could be decisive as it would leave their Spaniards needing to score three times to qualify.

Sevilla will look to strike force of Carlos Bacca and Kevin Gameira, who is optimistic they can qualify for the semi-finals

"Porto are a good side, but we are playing at home. It is a tough game, but we have to win to continue with our adventure in the Europa League," said the Frenchman.

The good news for Sevilla coach, Unai Emery is that he will have defender Federico Fazio and midfielder Stephane Bia available after they missed the first leg through suspension, although Portuguese defender Daniel Carrico will be an injury doubt until the last minute.

If Sevilla have a difficult task, Valencia's looks to be almost impossible following their 3-0 humiliation in Basil a week ago. Juan Antonio Pizzi's team produced their worst performance since he was named coach at the end of December. They were totally outplayed by last year's semi-finalists, despite Basil having the handicap of playing in an empty ground as the result of a UEFA punishment for crowd trouble.

Things have gone little better for Valencia in the La Liga in recent weeks and they now sit in mid-table no-man's land after a home defeat to Getafe and a 0-0 draw in Valladolid.