The midfielder has been linked to a reunion with his former manager Mauricio Pochettino at White Hart Lane, with the Sun claiming a move could be on the cards.
According to their report, the Argentine has asked chairman Daniel Levy to sanction a £20million move for his former Southampton star.
Liverpool could be tempted by that price given the player has struggled to find his best form since making the move from St Mary’s.
Hamann though, says he would be surprised to see it happen as he can be a game changer for Jurgen Klopp’s side.
“If Lallana were to leave, it would be a big surprise because he has come good lately and shown improved form under the new manager,” he told talkSPORT.
“Unfortunately he hasn’t done it often enough for Liverpool but I wouldn’t give up the ghost. If the penny drops, he is a game-changer and with Firmino, Coutinho and either Origi or Sturridge.”
It certainly would be surprising to see Lallana leave given how he has picked up under Klopp.
Indeed, from day one he has looked like the one player in the squad to have fully embodied the German’s philosophy.
Klopp is likely to want to keep him as a result of that, although a big money bid from Spurs would also surely be tempting.