Liverpool have signed midfielder Wataru Endo from Stuttgart for a fee of about £16.2m.
The 30-year-old Japan international has agreed a four-year contract.
Liverpool have brought in Endo after missing out on Ecuador international Moises Caicedo and Belgian midfielder Romeo Lavia to Chelsea.
Endo’s signing has been criticised due to his age, but Jurgen Klopp tried to ease those concerns by comparing him to James Milner.
He said: “He is a late bloomer in his career and he was definitely underestimated for a long time. It is clear he has improved every year since he was on the proper football screen.
“There’s no chance that anybody could [think he is 30], when you see him, you think, ‘Is he allowed to drive a car?’. On the pitch, he turns into a real monster.
“One of the biggest LFC legends of my time was James Milner, he arrived here when he was 29. I can tell you without James Milner, we wouldn’t have enjoyed success in recent years.
“Wataru can have a similar impact. The last week was obviously a tricky one. But when you have a problem you can stick to the problem or find a solution, I’m more than happy to have the solution.”