The former Benfica striker's first season at Anfield has been underwhelming.
And Aldridge wrote for the Liverpool Echo: "I have my concerns about Darwin Nunez. It's the injuries more than anything, though the early sending off didn't help him. The forwards before him didn't have the injuries.
"He's shown what he's about at times though, and he's a crowd-favourite. He's got a little bit of Luis Suarez in him, but probably without the finishing touch.
"But I think he'll get better. You're looking at a centre-forward who's been playing on the left-wing. And Cody Gakpo's a left-winger who is playing as centre-forward. That doesn't happen overnight.
"They've shown desire and eagerness in certain games, and he's scored goals. That's why the manager needs to have a look at the balance of the front three.
"We've been lucky to have them three players for years, Firmino, Mane, and Salah, and they weren't getting injured. Now Jurgen Klopp's got to get the right blend going forward and get the right back-ups as well."