Aldridge is concerned with Trent Alexander-Arnold, Virgil van Dijk and Mohamed Salah still having contracts which are running down.
He wrote for the Liverpool Echo: "Liverpool are looking like they will be leaving themselves with lots to do in the transfer market this summer, the way things are at the moment. There’s going to be a lot of movement.
"If Trent goes, we still don’t know what’s going to happen with Mohamed Salah and Virgil van Dijk’s contracts. You don’t want too much change. I don’t like to see what Chelsea do each summer with six, seven or eight new players. You can’t do that.
"You keep tweaking it every year. But we’ve maybe overlooked it. Last year we didn’t bring anyone in, apart from Chiesa who hasn’t played.
"This summer, how many will there be? Four? It’s got to be at least four. But if two or three of the players out of contract go, that becomes more. If any other big players go, it becomes more.
"We currently need a couple of players but could end up needing another five players coming in. It would have to be, and then it’s a big ask to gel five players into the squad."