Sterling emerged as a key player for the Reds in their ultimately unsuccessful quest for the Premier League title last term, scoring nine goals and creating five assists.
The 19-year-old was switched from a traditional winger to a central attacking midfielder for the final few months of the campaign and the youngster thrived.
Sterling's fine form was rewarded with a place in the England World Cup squad, and the teenager turned in an eye-catching performance in the 2-1 defeat to Italy in the Three Lions' opening game.
Following the departure of Luis Suarez - who moved to Barcelona for around £75 million last month - Skrtel is of the belief that Sterling can grow even more and become one of the side's biggest stars, in a campaign that includes a return to the Champions League.
Speaking to the club's official TV station, the Slovakian centre-back said: “I remember him when he joined the first team and he was a kid, and I can say he still is because he is still very young, but the things he is doing on the pitch is unreal.
"It’s unbelievable, and I’m very happy about that because Raheem is a very nice guy. He is working very hard and he showed last year he is a great player. At the moment, he is a very important player for us and England as well and I hope he will carry on that."
Skrtel is also hopes that Daniel Sturridge can embrace the role of being the club's "main man" in the striking department, following the sale of Suarez.
Sturridge scored 21 goals last term, and Skrtel has backed the England international to prosper in the absence of PFA and FWA Player of the Year Suarez.
“He will be the main man and the main striker and I just hope that he can stay fit and he doesn’t get any injuries, because that’s the main thing for every single player," he added.
“He’s a great player, he’s scored a lot of goals for us and I hope he will get more next season as well."
Liverpool finish their pre-season preparations with a visit of Bundesliga side Borussia Dortmund before they kick off their Premier League campaign with a visit from Southampton on August 17.