Rodgers convinced Allen will be huge Liverpool star
Both men return to former club Swansea City today.
"I think he's stepped up. Joe has come in and the biggest credit you can give him is the supporters have really taken to him," said the manager.
"Normally it takes players time to adjust to Anfield and the size of this club and the transition has been fairly smooth.
"In the last couple of games he's not been at the level he would want to be but there are all sorts of reasons: he's been playing a lot and he's just become a father so he's had many sleepless nights.
"But he will be a revelation for the club. He's been terrific and I am sure that will continue over the next number of years."