McManaman insists he wasn't surprised by the manager's impact.
He told liverpoolfc.tv: "I joined as an apprentice when I was 16 and Kenny signed me as a pro two years later. It was Kenny who gave me my chance and I learned a lot from him.
"He has this great way of dealing with people. Whether it's the person who works in reception or the guy on the car park, everyone has a high opinion of him.
"Players love playing for him and he commands respect. He was a great player himself so he's been there and done it. He knows what works and what doesn't work.
"People I speak to at the club now talk about how much the atmosphere has changed. They are more relaxed.
"Kenny has also brought back the old Liverpool values which were so admired. Everything is done behind closed doors and what goes on in the dressing room stays in there.
"All that combined makes for a happy group of players and when you've got that you find they try more for the manager."