"I have been working hard in the physio room and the gym just waiting for the moment when I could get back and work towards my chance to get in the squad," says the 18-year-old.
"I have to take my time, not rush things and expect too much. I need to gain a lot of fitness. I felt really tired at the end of the game at Sheffield even though I had played only 45 minutes.
"First-team football is totally different to youth or reserve level. The game is a lot faster and the defenders close you down a lot more quickly so you need that extra yard of sharpness.
"It is only a week and a half since I came back and I feel that given the time I can progress a lot more."
With Sturridge having made such an immediate impact on Sunday, there will be calls for him feature once again starting with Wednesday night's game against Derby, but the player is not expecting to be an automatic selection.
He told MCFCTV: "The fact that Sven picked me to be on the bench at the first opportunity he had was a great boost to my confidence and I hope I can go on and make the most of any opportunity that comes my way.
"I feel the cup appearance was a bonus and people shouldn't expect the manager to pick me every week. I am still learning and getting fit. It will be better for me to take things slowly."