Pep Guardiola's side make the journey to the Estadio Jose Alvalade on the back of collecting seven points from their first three Champions League games of the 2024-25 season, a strong start that has them third in the 36-team table behind Aston Villa and Liverpool.
However, the Citizens have faltered domestically over the past week, being knocked out of the EFL Cup by Tottenham Hotspur and suffering a shock 2-1 loss to Bournemouth in the Premier League to lose their grip on first place in the top-flight table.
To make matters worse, Pep Guardiola has been grappling with a mini injury crisis over the past couple of weeks, and the City boss was handed another huge worry when Haaland briefly went down in agony on Monday.
The 24-year-old was taking part in a rondo drill before going down to the turf clutching his lower leg, although he eventually managed to make it back to his feet and continue with the exercise.
Haaland included in Man City squad for Sporting trip
The Norway international does not appear to have any lasting damage, as City have confirmed that he is one of 22 players boarding the flight to Portugal for Tuesday's league phase game.
Guardiola may be quizzed on Haaland's fitness in his pre-game press conference later on Monday evening, but the Scandinavian will seemingly be fine to lead the line against Ruben Amorim's team.
Haaland has already netted three times in the current Champions League campaign, scoring once in the 4-0 thrashing of Slovan Bratislava before bagging a brace against Sparta Prague on October 23.
All in all, the former Borussia Dortmund striker has had a direct hand in 49 goals in just 42 appearances in the Champions League, and he could now break the record for reaching 50 involvements in the quickest time.
The current record holder in that category is Ruud van Nistelrooy, who reached 50 Champions League goal involvements in 46 matches, but Haaland could now achieve the half-century in three fewer games than the current Manchester United interim boss.
Who else is in and out of Man City squad?
Prior to the loss to Bournemouth, Guardiola exclaimed that he could only have 13 senior players available at the Vitality Stadium due to injuries, although he was able to welcome all of Kyle Walker, Savinho, Jeremy Doku and Kevin De Bruyne back to the squad.
All four have also made the journey to Portugal, but Ruben Dias, John Stones and Jack Grealish will not be involved in Tuesday's match, nor will long-term absentees Oscar Bobb and Rodri.
With five senior players missing, Guardiola has reinforced his ranks with a handful of academy players, calling up Nico O'Reilly, Jacob Wright, Jahmai Simpson-Pusey and Josh Wilson-Esbrand to face the Primeira Liga leaders.
City last met Sporting in the last 16 of the 2021-22 Champions League, where Guardiola's side strode to a 5-0 win away from home before confirming their place in the last eight with a goalless draw at the Etihad.
However, the Premier League champions are now facing a Sporting side who have won each of their opening 10 Primeira Liga matches of the season, although Tuesday's game will be Amorim's last Champions League contest in charge of the club before he takes over as Man United manager.