The Italy international joined the Reds as a replacement for Alonso, who joined Real Madrid.
“He was a very important player at this club,” said Aquilani.
“But I am not his natural substitute as I do not have the same characteristics as him.
“I have a different style in that I like to move around and not stay in the same place.”
Aquilani will be out until October with an injury.
“At Roma my worries were linked with injury. But when I came to Liverpool, the doctor highlighted exactly the problem I have,” added Aquilani.
“We now have a very good picture and I hope it will be solved so that I will not be absent again.
“It is a shame I cannot play straight away but it is important to get better, then play well. I am focusing on that.”
