The England international missed most of the Reds' pre-season preparations though injury, but returned in time to score the only goal in a 1-0 win over Stoke City
Sturridge struck the only goal of the game in Saturday's 1-0 victory over Stoke City at Anfield as Liverpool began the Premier League campaign with an encouraging performance.
An ankle injury sustained while on international duty with England back in May had threatened to leave the striker unavailable to Rodgers for the opening month of the season.
The 23-year-old, though, battled back to full fitness ahead of schedule and Rodgers thinks the January signing from Chelsea is in excellent shape due to his commitment and attitude.
"I think the biggest credit you can give him is that in all the time he was off, he never put on any weight whatsoever," said Rodgers.
"His body fat remained the same as when he was playing, which shows you how hard he was working.
"And I have to give credit to the medical team, because they've got to make sacrifices as well.
"Daniel was keen to get himself right, so he was ready to fire at the beginning of the season.
"For a bit of time it was touch and go, but once we saw his progress and how he was working, he was back probably three weeks earlier than what we anticipated, purely because of his attitude.
"I always believe he's got a goal in him.
"That's why we took him here. As long as he's on the field, he can end up being one of the top goalscorers in this league."