Five talking points ahead of this week's Europa League action

Manchester United and Arsenal are back in Europa League action on Thursday with the competition reaching the quarter-final stage.

United head to Spain for their first leg with Granada, while Arsenal are at home to Slavia Prague.

Here, the PA news agency looks at the main talking points.

Green shoots for Greenwood

Mason Greenwood 's return to scoring form spells good news for United's run-in. Greenwood burst onto the scene last season with 17 goals, but the has only managed six this time around. Greenwood was back on the scoring trail against Leicester and Brighton - the first time he has scored in successive games this term - and a late-season flourish could boost United's silverware hopes and push the 19-year-old towards England's Euro 2020 squad.

Solskjaer goalkeeper call

United boss Ole Gunnar Solskjaer has another difficult choice ahead of him after preferring Dean Henderson to David De Gea for Sunday's Premier League victory over Brighton. Henderson appears to be the United number one for now and has started all four of their Europa League games. De Gea has not played since February 28 after returning to Spain for the birth of his first child and will hope to get game-time and show that his Old Trafford career is not over.

Granada threat

Until now, Granada was best known in Manchester for being the name of the ITV franchisee for the north west of England. Granada were in the fourth tier of Spanish football as recently as 2005-06 and this is their second season back in LaLiga following relegation in 2017. Granada finished seventh in Spain last season to qualify for the Europa League for the first time and have progressed from the second qualifying round by beating the likes of Molde, Napoli and PSV Eindhoven. Notable players include former Tottenham striker Roberto Soldado and on-loan Chelsea winger Kenedy.

Arteta ambition

Arsenal boss Mikel Arteta admitted he was "in shock" after Saturday's 3-0 Premier League loss to Liverpool. The contest was so one-sided, debate turned quickly to whether Arsenal have improved under Arteta. The Spaniard's win percentage in the league from his first 50 games in charge is only 42 per cent. His predecessor Unai Emery, now in charge of fellow Europa League quarter-finalists Villarreal, had a 49 per cent win percentage from his 51 games there. Exciting youngsters like Bukayo Saka and Emile Smith Rowe have emerged, but Arteta needs to see signs of real improvement against Slavia Prague to silence some of the background noise.

Kudela absence casts shadow

Slavia Prague defender Ondrej Kudela will not be at the Emirates. Kundela has been handed a provisional one-match ban after being accused of racially abusing Rangers midfielder Glen Kamara last month. Kudela faces a minimum 10-game ban if found guilty of insulting the "human dignity" of Kamara on the grounds of his skin colour and race, but his no-show in London has prevented Police Scotland from questioning the 34-year-old with regards to their criminal investigation against him.