Saunders reckons midfielder Allen is good enough to play for Barcelona.
He told the Daily Star: "Joe's an intelligent player, has a heart like a lion and is difficult to play against.
"He's got the whole world in front of him. He's still growing and he'll get stronger and stronger.
"He'll be harder to push off the ball while tactically he'll become more aware too.
"He's a good lad, he wants to listen and very respectful of authority which you must have to be a top player."