Darren Fletcher returned from his career-threatening bowel condition as United scrambled to an unconvincing Champions League win.
It was the Scot's first appearance since November 22, although he had been battling against the problem for eight months before that.
At one stage, Sir Alex Ferguson admitted he feared whether Fletcher would ever resume his career.
Fletcher's arrival for Paul Scholes 11 minutes from time brought a deserved standing ovation, and was one of the few high points of a difficult evening for the hosts, who collected the victory but little else of note.
Carrick's first Champions League goal in three years after just seven minutes proved enough, with United missing yet another penalty, their third of the season, through Nani.
Galatasaray were desperately unlucky, failing to get a clear penalty before United struck, hitting the woodwork twice before being denied by David de Gea's excellent double save and then having another spot-kick claim waved away in stoppage time.
Such was the significance of Fletcher's presence on the United bench that it even overshadowed Robin van Persie and Shinji Kagawa both being given their European debuts.
Both were involved in Carrick's early opener.
Initially, van Persie threaded a pass through to the midfielder. It was Kagawa who got the main credit though, slipping a return pass beyond the visitors' defence. Carrick stepped inside goalkeeper Fernando Musiera and even though the goalkeeper tripped him, the England man was able to steer the ball in.
The incident did beg the question of inconsistencies within the rules. Had Carrick fallen for the penalty, Musiera would have been sent off and Galatasaray's position substantially weakened.
As it was, whilst a goal down, they were also able to mount a comeback bid.
Mind you, the Turkish champions already had cause to grumble.
Sold short by Patrice Evra's lay-off, Nemanja Vidic lunged in on Umut Bulut.
Referee Wolfgang Stark might not have seen the clear foul. There was no excuse for the goal-line assistant missing it. Yet somehow Vidic, and United, escaped.
Galatasaray's response to falling behind was for Nordin Amrabat to clip the crossbar with a curling shot from the edge of the area that gave returning keeper de Gea no chance.
It was not the last time Galatasaray struck the woodwork - Hamit Altintop was the unlucky man second time around after a free-kick had been rolled into his path. Again De Gea was rooted to the spot, thankful to see the ball flick wide of his left-hand post.
Having called for defensive solidity, Ferguson, who brought in Jonny Evans for Rio Ferdinand, could not have been happy.
His side were not creating that much at the other end either.
Emmanuel Eboue did prevent former Arsenal team-mate van Persie from turning Antonio Valencia's low cross home at the far post.
Largely though, United's patient build-up broke down before they got within shooting distance.
In contrast, Altintop was almost Cristiano Ronaldo-esque in his desire to pepper De Gea's goal.
The shot that fizzed wide not long after the restart was his fifth, only two less than United had mustered as an entire team up to that point.
There then followed the third instalment of United's penalty embarrassment.
After failures from van Persie and Javier Hernandez already this season, Nani exuded confidence.
Until it actually came to striking the ball that is. After a little shimmy, the Portugal winger seemed to freeze, and Musiera saved to his right.
Galatasaray took it as the cue to launch another counter and this time Selcuk Inan guided his header marginally wide of the far post.
It was not convincing in the least, yet United's narrow advantage was almost turned into a winning one when Patrice Evra surged forward and saw his shot flick narrowly wide.
From the corner, United quickly lost possession as Nani appealed in vain for another spot-kick.
Galatasaray sped to the other end and De Gea, of whom so much is being asked, came to United's rescue with a superb double save, first to deny Burak Yilmaz, then Emre Colak, who seemed certain to finish off the rebound.
Rather than being eased in as Ferguson doubtless hoped, Fletcher's battling qualities were a necessity for the latter stages as United managed to keep their opponents at bay.
It was never comfortable though, with substitute Javier Hernandez failing to capitalise on a couple of late opportunities before Aydin Yilmaz had another spot-kick claim waved away.