Ferguson saw Carlos Tevez level late on after Karim Benzema had given Lyon the lead after halftime. The United manager said: "The players showed great character and the difference this season is that we have strength in depth in our squad to see us through.
"Now I expect us to return to Old Trafford and finish the job. It was a setback to lose the goal when we did because I thought we were in control at that time.
"But the options we have on the bench are very good now and I was able to make the changes to help us get back into the game. When you score so late on, you're relieved because you can never be sure you will get an away goal."