The two teams have met twice before in European competition and on both occasions the away side came out on top in the 2015-16 Europa League group stage.
Match preview
Lech Poznan are competing in their first-ever European quarter-final after securing a comfortable 5-0 aggregate victory over Swedish outfit Djurgardens IF in the last 16.
Only Thursday's opponents Fiorentina (26) and West Ham United (19) have scored more goals than the Railwaymen (18) in this season's Europa Conference League, and John van den Brom's side have had no problems finding the net over the last few months as they have scored in each of their last 10 games across all competitions.
Poznan extended their unbeaten run to seven matches with a routine 2-0 win over city rivals Warta Poznan last weekend, with Michal Skoras netting a brace to increase his goal tally for the season to 15.
The Polish side's hopes of retaining the Ekstraklasa title appear to be over as they sit third in the table and 14 points behind leaders Rakow Czestochowa, who have a game in hand, but a top-three finish is still achievable for Van den Brom's men and progress in Europe is also high on the agenda.
Poznan will be confident of success on home soil on Thursday having already won seven and drawn one of their eight Europa Conference League matches - including qualifiers - at Stadion Poznan, with this impressive unbeaten run including a notable 3-0 group-stage win over Spanish side Villarreal.
However, the Railwaymen lost their only previous home encounter against Fiorentina, losing 2-0 back in November 2015, and will be wary of the Italian side's impressive unbeaten run heading into Thursday's first leg.
Since failing to win their opening two Europa Conference League group-stage matches against Rigas FS and Istanbul Basaksehir, Fiorentina have put together an eight-game winning streak in the competition, scoring 25 goals and conceding only four.
La Viola ran out 5-1 aggregate winners against Sivasspor in the last 16, following up a slender 1-0 home victory with a comfortable 4-1 success on the road.
Vincenzo Italiano has also turned the club's fortunes around domestically as they have won six and drawn two of their last eight matches across Serie A and the Coppa Italia; a five-game winning run was brought to an end last weekend, though, as they drew 1-1 at home to Spezia.
Nevertheless, Fiorentina have moved to within seven points of the top six in Serie A with nine games remaining and head into Thursday's clash in buoyant mood as they bid to gain a first-leg advantage over Poznan and boost their chances of progressing to their first European semi-final in eight years.
La Viola will fancy their chances of coming out on top in Poland, having won each of their last six away matches, including each of their last four in the Europa Conference League by an aggregate score of 14-1.
Lech Poznan Europa Conference League form:
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Fiorentina Europa Conference League form:
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Fiorentina form (all competitions):
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Team News
Poznan will have to cope without forward Filip Szymczak as he continues to recover from a knee injury, while midfielder Radoslaw Murawski is suspended for the first leg.
A back four of Joel Pereira, Antonio Milic, Bartosz Salamon and Pedro Rebocho is set to remain intact, with former Leeds United left-back Barry Douglas forced to settle for a place on the substitutes' bench once again.
Winger Skoras and striker Mikael Ishak, who have scored 10 of Poznan's 18 goals in the Europa Conference League this term, are expected to keep their places in attack and could be joined by either Adriel Ba Loua or Kristoffer Velde.
As for Fiorentina, Luka Jovic - the current top scorer in this season's Europa Conference League with six - recovered from illness to feature as a substitute last weekend, and the striker will be pushing to start up front ahead of Arthur Cabral, who has scored five goals in his last five matches in European competition.
Nikola Milenkovic has also recovered from illness and will push to start at centre-back ahead of either Igor or Lucas Martinez Quarta, while La Viola's only injury concern is with goalkeeper Salvatore Sirigu, who remains sidelined after undergoing Achilles surgery at the beginning of this month.
Moroccan midfielder Sofyan Amrabat is available for selection after serving a domestic ban last time out, and he will likely replace Gaetano Castrovilli in the first XI, while Riccardo Sottil, Riccardo Saponara and Nicolas Gonzalez will all battle to start on the left flank.
Lech Poznan possible starting lineup:
Bednarek; Pereira, Salamon, Milic, Rebocho; Karlstrom, Kvekveskiri; Skoras, Sousa, Velde; Ishak
Fiorentina possible starting lineup:
Terracciano; Dodo, Milenkovic, Igor, Biraghi; Mandragora, Bonaventura, Amrabat; Ikone, Cabral, Gonzalez
We say: Lech Poznan 1-2 Fiorentina
Both teams have enjoyed strong runs of form both domestically and in Europe in recent months and will be confident of picking up a valuable first-leg win on Thursday.