Neither side has picked up a point from games against Ajax and Borussia Dortmund, so will be desperate to come out on top in the first of back-to-back matches between the champions of Turkey and Portugal.
Following defeat at the hands of group favourites Dortmund on the opening day, Besiktas could have been forgiven for travelling to Amsterdam for their second Group C fixture in trepidation, considering Ajax's exploits in Lisbon.
The Dutch club continued where they left off after their first day 5-1 win, as they took a two-goal lead over the Turkish champions before half-time. Though Ajax ultimately had to settle for a 2-0 scoreline at the Johan Cruijff Arena, Beskitas were blown away, as they conceded 22 shots on goal and had just 29% of the ball.
Two defeats to start their campaign, then, leaves Sergen Yalcin's side needing to put points on the board quickly, as they approach a pair of potentially destiny deciding games against the Primeira Liga champions.
Curiously, the Black Eagles have never won at home to Portuguese opponents in eight previous attempts, so will have the weight of precedent against them on Tuesday, which they hope will be countered by the vociferous support of their fans.
Preparations have not gone perfectly, though, as they were beaten 3-2 in a dramatic capital derby with Istanbul Basaksehir on Friday night. Italian forward Stefano Okaka grabbed a brace for Basaksehir, as the 2019-20 Super Lig winners got the better of their successors, who lost for the second time in the league this term despite goals from Alex Teixeira and Michy Batshuayi.
Yalcin therefore sees his side - which kept clean sheets in each of their first four league games this season, but have shipped 11 goals since - trailing title rivals Fenerbahce and Trabzonspor in the standings, having accumulated 17 points from their first nine matches.
His focus now switches to continental matters, and keeping alive dreams of at least matching the last time Besiktas made it through to the knockout stages, in 2017-18 - when they won their group unbeaten ahead of Porto, Leipzig and Monaco but were then beaten by Bayern Munich in the last 16.
Sporting's ninth Champions League group campaign - and first in four years - has so far followed a similar trajectory to that of their hosts this Tuesday.
Following a rude awakening against Ajax at the Alvalade - when they conceded four goals to Ivorian striker Sebastien Haller alone - the Lisbon club made a much greater fist of their visit to Dortmund on matchday two, late last month. In a close-fought and somewhat scrappy encounter, only Donyell Malen's first goal in the colours of BVB separated the sides, as Sporting slipped to a second straight defeat.
Resurgent under Ruben Amorim over the past 18 months, the Lions recorded a 2-1 victory over Arouca in their last game before the international break; moving them onto 20 points in the Primeira Liga - still unbeaten, but behind fellow 'Tres Grandes' rivals Porto and Benfica.
The defence of their first title in nearly two decades may have begun smoothly - and Amorim also oversaw a comfortable 4-0 victory at third-tier Belenenses in the Taca de Portugal on Friday - but significant European progress has proved elusive since a run to the Europa League quarter-finals in 2018.
If they are to regain ground lost so far in Group C, Sporting must now get the better of a side with whom they have been paired together only once before in UEFA competition.
In the Europa League group stage of 2015, the Iberians managed a 1-1 draw in Istanbul before winning 3-1 at home in the final round of fixtures - a result that took them through as runners-up at the expense of Besiktas. Such a set of scores on this occasion - with the return game set for early next month - would put them in the driver's seat for securing European football into next year.
While an injury list which decimated their squad for the defeat against Ajax has eased a little for Besiktas, several first-teamers will be absent on Tuesday.
Miralem Pjanic, Mehmet Topal and Georges-Kevin Nkoudou are all expected to miss out for the Black Eagles, who welcomed last season's top scorer Cyle Larin - who plundered 19 goals last term but has not found the net in six club matches since August - back to the bench on Friday.
The Canadian striker, who missed his nation's game with Mexico last week through injury, could support Michy Batshuayi up front, while Alex Teixeira will also hope to feature following his goal as a half-time substitute against Basaksehir.
In central midfield, Larin's compatriot Atiba Hutchinson should join Souza, and the right full-back role will be occupied by Frenchman Valentin Rosier, who joined Besiktas from Sporting on a permanent basis in the summer, after last season's loan.
The visitors, meanwhile, have not had a league fixture for over a fortnight, so internationals and cup commitments notwithstanding, should be in prime shape for the trip to Turkey.
Ruben Amorim made a host of changes as his team took on humble opposition on Friday, but established stars such as Pedro Porro, PSG loanee Pablo Sarabia and Joao Palhinha will return to the XI on Tuesday.
Captain Sebastian Coates is also back from South America to feature in the Sporting defence, but much-admired forward Pedro Goncalves - who struck 23 times in his club's march to the 2020-21 national title - continues to recover from a knee injury and is ruled out.
Besiktas possible starting lineup:
Gunok; Rosier, Welinton, Vida, Yilmaz; Hutchinson, Souza; Ghezzal, Ozyakup, Larin; Batshuayi
Sporting Lisbon possible starting lineup:
Adan; Neto, Coates, Feddal; Porro, Palhinha, Braganca, Reis; Sarabia, Paulinho, Tomas
We say: Besiktas 2-3 Sporting Lisbon
Both sides pose a threat in the final third and are capable of causing each other some serious defensive problems on Tuesday.
With everything to play for and several able attackers on display, the game should open up after its first goal, and Sporting can edge out their hosts by the odd goal due to shortcomings in the Besiktas back line.
body check tags ::
Previews by email