England international Sturridge missed five months with calf and thigh injuries, but made a goalscoring return as a substitute in a 2-0 win over West Ham at the end of January.
Another strike followed in Saturday's 2-1 FA Cup victory at Crystal Palace, booking a home quarter-final with Blackburn Rovers next month.
With Liverpool taking on Besiktas in the UEFA Europa League last 32 this week, and still harbouring hopes of finishing in the Premier League's top four, Moreno knows what an integral role the striker could play.
"You just have to watch him play to see how important he is," he told the club's official website.
"After being injured for so long, he scored a goal with his second touch [against West Ham]. You can see the type of footballer he is from that.
"Sturridge is a top player and everyone on the team was wishing he returned as soon as possible - and he's done brilliantly. He's a very important player for the team."
Moreno was also full of praise for 19-year-old winger Jordon Ibe, who has impressed since making only his second Premier League start at Everton earlier this month.
"He is still so young and is showing his value already," Moreno said. "He's young, strong and fast - and he can play brilliantly using both feet.
"As well as that, he is from the Liverpool academy and the fans enjoy having a first-team player from the club's academy.
"I bet he will turn out to be a very important player for Liverpool and a great footballer."
