What to watch out for in this week's second legs

Ghosts of Old Trafford past
It looked like going from bad to worse for United when they fell behind to a stunning West Ham goal on Sunday but they showed great character to salvage a draw and FA Cup quarter-final replay. Now they must do the same and then some against Liverpool. They were summarily outplayed in the first leg, grateful for David de Gea's heroics, but Old Trafford is a different stage and one that has witnessed more than its share of stirring comebacks over the years. "We have a second chance and it is possible," says Marouane Fellaini. "We can score goals – we've done it before."
Man. United v Liverpool, 21.05CET

Klose relief for Lazio
Miroslav Klose scored his first goal of the season in the round of 32 return leg against Galatasaray and broke his Serie A duck at the weekend, striking twice as Lazio defeated Atalanta 2-0. "It was a weight off my shoulders," the German forward said. The 37-year-old has played just 107 minutes of UEFA Europa League football this term, but may feature against Sparta, with the tie level at 1-1. Lazio coach Stefano Pioli is hungry for success. "Reaching the last eight would be good, but not enough for us," he said.
Lazio v Sparta, 19.00

Longest unbeaten streak for Fenerbahçe
Last week's 1-0 victory over Braga took Fenerbahçe to eight European fixtures unbeaten, their best ever single-season run. The Turkish Super League leaders will be sure of a quarter-final place should they avoid defeat in Portugal. Braga lost 3-0 on Sunday, yet they rested players and coach Paulo Fonseca is up for the European challenge. "We know it won't be easy," he said. "We will be playing at home, but we will be starting the game 1-0 down against a great team."
Braga v Fenerbahçe, 21.05

Sevilla home in on history
Holders Sevilla will rely on their imperious home form as they bid to become the first team to make it to the last eight of the UEFA Europa League three seasons running. Although not managing to score an away goal in Basel could count against them, Unai Emery's side have a habit of making home advantage count – they have won their last 16 matches in all competitions at the Sánchez Pizjuán. "When we're at home anything is possible," said defender Adil Rami. "We have a 12th man."
Sevilla v Basel, 21.05

Does Inter near-miss show Spurs how it is done?
No club has ever recovered a three-goal deficit at this stage of the competition, though Tottenham know from almost bitter personal experience that it is not beyond the realms of possibility. Three years ago the English team took a 3-0 cushion to Internazionale Milano but were seemingly powerless as Inter patiently reduced the arrears, eventually forcing extra time. Spurs were indebted to Emmanuel Adebayor's strike in the additional 30 minutes as they prevailed on away goals and, 36 months on, they could do a lot worse than reviewing that night.
Tottenham v Borussia Dortmund, 21.05

Valencia summon spirit of 2014
If overturning a 1-0 deficit against in-form Athletic looks a daunting task, Valencia can draw strength from their incredible fightback against Basel in 2014. The Liga outfit lost 3-0 in Switzerland but a Paco Alcácer double helped set up a 3-0 win at Mestalla to take the contest to overtime, where Alcácer struck again along with Juan Bernat, sending the home fans into ecstasy. Coach Gary Neville would love a repeat of that special occasion. "We need an incredible atmosphere, the fans will give us that, so we need to match it on the pitch," he said. "We have to make it a special night."
Valencia v Athletic, 19.00

Defensive breaches offer comfort for Leverkusen
Villarreal's campaign has been built on the soundest of defensive foundations yet, for the first time this term, cracks appeared at the weekend as they conceded four at Sevilla. That offers some hope to Leverkusen, who must net at least twice if they are to overturn their 2-0 first-leg reverse. Perhaps the biggest factor in the German team's ambitions is not scoring themselves, rather keeping out Cédric Bakambu (four goals in two games) at the other end.
Leverkusen v Villarreal, 19.00

Acheampong key to Anderlecht hopes
Before 5 February, Frank Acheampong had managed one goal all season. He has since plundered seven in nine outings, including four goals and an assist in three UEFA Europa League matches. Shakhtar struggled to cope with his pace and direct running in the first leg, and if Anderlecht are to conjure an unlikely comeback from 3-1 down you suspect the 22-year-old will have to be at the heart of it. Acheampong, for one, is optimistic. "If it had stayed 2-1 we would have had a good chance," he said. "Now it is more difficult, but I believe it is possible."
Anderlecht v Shakhtar, 21.05