MADRID, March 6 (Xinhua) -- Three Spanish sides are in action on Thursday in the first leg of their last 16-Europa League ties.

Sevilla go into their game at home to Slavia Prague trying to forget a disastrous run of domestic form which has seen them lose six of their last eight matches in the Liga Santander and drop out of the top-four, leading to the future of coach Pablo Machin coming under question.

"I can't deny that there is a certain amount of worry, but I also think that thinking too much about this is wasting energy. I think we have to focus on Europe, where we have been very reliable. I have the confidence of the people who appointed me in the first place and I don't want to let them down," said Machin in his pre-game press conference.

Valencia travel to Russia to face Krasnodar after a good week which saw them book their place in the final of the Copa del Rey, where they will face FC Barcelona, and a 2-0 win at home to Athletic Club Bilbao, which has lifted them to seventh place in the league table.

Krasnodar will be tough rivals for Valencia as they are currently second in the Russian league behind the powerful Zenit St Petersburg.

Zenit are the rivals of the third Spanish representative in the tournament, Villarreal, who travel to Russia third from bottom of the table in Spain, but looking for a performance to boost their moral.

Villarreal left back Jaume Costa pointed out that in the last round his side knocked Sporting Lisbon out of the last round of the Europa League and followed that up with a 3-0 win at home to Sevilla in the league, and said he hoped the same could happen if they got a good result in St Petersburg.

Villarreal have a vital league game away to Levante on Sunday and coach Javier Calleja will make changes to his starting 11 with the need for three points in mind.