Roberto Mancini returns to his homeland - where he spent many a season battling the Bianconeri - two days after being confirmed as Gala's new coach.
Fatih Terim paid the price for a poor start to the season that has yielded just one win in five league matches, as well as the disappointing showing against Real in front of the home supporters.
The Super Lig champion was outclassed by the Spanish giant in the Group B opener, with Cristiano Ronaldo once more stealing the show with a second-half hat trick in the comfortable rout.
Mancini, who has been out of work since being fired from Manchester City in May, took control at the Turk Telekom Arena on Monday.
Galatasaray heads into the fixture at the Juventus Stadium on Wednesday on the back of a 1-1 draw at home to Rizespor. Engin Baytor opened the scoring, but Tevfik Kose levelled in the second half before Slcuk Inan saw red.
Midfielder Hamit Altintop continues to be plagued by a hip injury and is likely to miss the visit to Turin.
Reigning Serie A champion Juventus will be desperate to claim a maximum haul after a disappointing 1-1 draw away to Copenhagen in its opening fixture.
Antonio Conte's team is in good form ahead of Wednesday's showdown and is on an eight game unbeaten run in all competitions.
The club will look to build on the momentum from its 1-0 victory over Torino at the Stadio Olimpico on Sunday, with Paul Pogba's second-half header securing the points.
Juve could be without influential striker Carlos Tevez after he picked up an ankle injury against Torino following a robust challenge from Ciro Immobile.
The Argentine has notched three times in the league for the Turin outfit since his move from Manchester City.