Rodgers has insisted he knew it was no gamble in signing the 22-year-old, slamming 'snobbery' surrounding smaller clubs and claiming Allen has been Liverpool's best player this season.
He told WalesOnline: "It was never a risk. There was no doubt for me because I've always said the boy is a top player - and he's proven that in the short period of time he's been here.
"Like myself, he wasn't crying to leave Swansea, but I knew he could help define the philosophy which we're starting and looking to form. He's been a massive revelation and it's great credit to Swansea and his upbringing that he has come in here and been arguably our best player.
"He's been phenomenal with his precision in his passing, his technique and his vision.
"And it's great for Liverpool supporters because they were probably not sure of the £15m fee - but they have been surprised. Sometimes there is a snobbery towards players of smaller clubs, but top players weren't just dropped out of heaven.
"They have to start out somewhere. Joe's just got an in-built brain for football and life. He's a very humble kid.
"He's just strolled in here and not many people will have known him.
"But if you ask anyone here, including the players, they will know him now."