Ferguson was constantly shuffling his defensive cards last season with first-choice central defenders Nemanja Vidic and Rio Ferdinand playing alongside each other only once in six Group C matches, two of which United drew at home.
United drew 3-3 at Old Trafford with Basel and 2-2 with Benfica as they failed to reach the last 16, one of the reasons given for a three percent dip in total revenue in the year to June.
While Ferguson admitted his side had been careless at home last season, he said injuries to key defenders had not helped.
"I think the key is to keep the defenders fit," Ferguson, whose side are drawn with Galatasaray, Braga and CFR Cluj, told a news conference on Tuesday.
"I mean that. We had a rough ride with defenders being injured in the last two or three years. If they remain fit that gives us a better opportunity."
Injuries to Chris Smalling and Phil Jones have again reduced Ferguson's options as he prepares for Wednesday's home clash with the Turkish side, although Ferdinand and Vidic are both fit.
"If I could be guaranteed two would be fit for the rest of the season, I'd gladly take that right now," he said.
"That's not been the case over the last few seasons. It's a key issue for us and we can't hide it. I just hope we get a bit of luck in that respect."
The draw with Basel last September, when his team had looked to be cruising at 2-0 up, still irks Ferguson.
"Finishing off games has to be a driving force for us," he said. "We all agree we were careless in two of the games at home last season.
"The Basel game was the one where the criticism was quite right. We were 2-0 up and playing well and then got careless in the second half and ended up drawing 3-3.
"That ended up knocking us out really. We had to go there [to Basel] and get a result and we ended up chasing our tails. Hopefully our home form, which had been good for many years, will be good again this year."
Fergsuon said Shinji Kagawa was ready to play after missing the game against Wigan Athletic on Saturday with injury while David de Gea could be recalled in goal in place of Anders Lindegaard.
