It would be very natural for me, if this time Galatasaray was slightly superior to Manchester United. After all, the match was played at Rams Park, Galatasaray's headquarters. Apart from that, there are many factors that make United considered to have only a slim chance of winning the match against Galatasaray. Actually, I haven't collected all the information, especially for United. whether the injuries to Hojlund, Eriksen, the status of Rashford, Antony and others. So in this post, I will only opine based on what I know.
Clearly, Galatasaray is superior both in playing style and squad strength. In addition to the recent injuries to Hojlund, Eriksen, Casimiro, Luke Shaw, now Onana is also sidelined due to an injury while playing for the national team. Ten Hag is genuinely struggling with his current personnel situation. Fortunately, Bruno recently affirmed his future commitment to play for Manchester United, dispelling rumors of him moving to play in the Arab world, somewhat reassuring United fans.
Moreover, playing at Galatasaray's home ground, Rams Park, has never been easy for Manchester United. There's a significant psychological advantage for Galatasaray as they convincingly defeated United in the first leg despite playing at Old Trafford. So, there's no reason for them to drop points when playing at home in the upcoming match.