Runaway Austrian Bundesliga leaders Red Bull Salzburg travel to take on Basel on the back of an exceptional 14-match winning streak in all competitions.
They last tasted defeat in a 2-1 reverse at Rapid Vienna on November 24, and they are now an incredible 25 points clear of Grodig in the Austrian top flight.
Roger Schmidt's side hammered European giants Ajax 6-1 over two legs in the previous round, thanks in part to a stunning 3-0 win in Amsterdam. They travel to Switzerland as the top scorers in this year's competition with 21 goals from eight games in the competition proper, three more than anyone else, and they are they only side to have won all eight of their matches.
Jonathan Soriano will likely pose the greatest threat to Basel, the tournament's top scorer having netted 10 goals including qualifiers, with 36 to his name in all competitions this term.
He will look to Kevin Kampl and Alan for service, the duo recording the joint-most assists (four) of any players left in the competition. Defender Andreas Ulmer is absent with a knock, while Alan's invovlement is in question due to a muscular problem as they look to continue their free-scoring form and return to Austria with an advantage to take into the second leg in a weeks time.
Basel also top their domestic league, although their five-point advantage over a group of three chasing clubs looks slightly less comfortable when compared to their opponents' mammoth lead.
Murat Yakin's men reached last year's semi-finals before being knocked out 5-2 on aggregate by eventual winners Chelsea, and entered the competition in the knockout stages this time after a third-place finish behind Chelsea and Schalke in the Champions League.
They had a comfortable passage in the round of 32, drawing 0-0 with Maccabi Tel Aviv in Israel before a double from 14-goal striker Marco Streller helped them to a 3-0 triumph in the return leg.
The 32-year-old is doubtful for the clash with a thigh problem sustained in Saturday's 1-1 draw with St Gallen, while Ivan Ivanov and Endogan Adili are ruled out with knee injuries.