Paris - The Europa League knockout phase begins on Thursday, with VAR being introduced to Europe's secondary club competition for the first time outwith the final for the last 32, first-leg ties.
Here are five games to watch this week:
Man United in Bruges
Manchester United's Champions League aspirations have been given a major boost in recent days, first with the news of Manchester City's two-year ban from the competition. Then, on Monday, Ole Gunnar Solskjaer's side beat Chelsea 2-0 away to close to within three points of their opponents in fourth place in the Premier League.
Now they revert their focus to the Europa League, which could also offer them a ticket to next season's Champions League if they reach the final in Gdansk in May and lift the trophy.
United head to Belgium to take on Club Brugge in the first leg of their tie. Beaten by Liverpool in two European finals in the 1970s, Club Brugge are not a side to be taken lightly. They dropped out of the Champions League group stage despite holding Real Madrid away, and are nine points clear atop the Belgian league.
Arsenal 'deserve our respect'
Arsenal are unbeaten in their last eight games under Mikel Arteta, although the Gunners' new Spanish boss could do with turning some of his team's many draws into more victories.
Currently in mid-table in the Premier League, last season's beaten finalists travel to face Olympiakos knowing this competition is surely their best bet if they are to return to the Champions League next term.
"They may not have started well in the Premier League this season, but they have great players, are dangerous and deserve our respect," said Pedro Martins, the coach of Olympiakos.
The Greek league leaders dropped out of the Champions League group stage despite holding Tottenham Hotspur to a 2-2 draw in Piraeus.
Ajax set for battle in Spain
After enchanting Europe on their run to the Champions League semi-finals last year, Ajax were brought crashing back to earth when they were eliminated from this season's competition in the group stage.
The Dutch champions were then handed a tough Europa League draw against a Getafe side who have been one of the stories of the season in Spain.
The unfashionable outfit from the working-class satellite town just south of Madrid finished fifth in La Liga last season and are currently third under Jose Bordalas, whose his idol as a youngster was Johan Cruyff.
"They are warriors. They fight for every ball and really give everything," Ajax star Dusan Tadic told Dutch daily Algemeen Dagblad. "They are physically very strong and go beyond the limits if necessary."
It is Getafe's first European knockout tie since they took Bayern Munich to extra time in the UEFA Cup quarter-finals in 2008.
Will Salzburg survive without Haaland?
Erling Braut Haaland's eight goals were not enough for Salzburg to qualify from the Champions League group stage, and the Austrians have since lost their striker to Borussia Dortmund. Japanese winger Takumi Minamino also departed for Liverpool, leaving them looking seriously weakened for the second half of the season.
Salzburg did sign Swiss starlet Noah Okafor, but their first league game after a long winter break ended in a 3-2 home defeat by title rivals LASK Linz last weekend.
Now Salzburg face Eintracht Frankfurt, meaning a reunion with Adi Huetter, who coached Salzburg to a league and cup double in 2015.
Celtic fairytale in Copenhagen?
Celtic have been eliminated at this stage in the last two seasons but should fancy their chances against FC Copenhagen as they head to Denmark.
While Celtic have claimed nine straight wins this calendar year, Copenhagen's first league game of 2020 ended in defeat last weekend.
Current Celtic manager Neil Lennon was a player when the Glasgow giants lost 3-1 on their last trip to Copenhagen in the Champions League in 2006.
His team qualified by topping their group, and of this tie he said: "It's great to have European football after Christmas, and it's a tough draw. It could have been tougher, but it could have been easier."