Alexander-Arnold's future at Real Madrid hangs in the balance, with current manager Álvaro Arbeloa recently suggesting that the England international could leave once the summer window opens.
Manchester City have been linked with the 27-year-old, but the biggest story is his potential return to the Reds, who are in the midst of a defensive crisis brought on through injuries to Jeremie Frimpong and Conor Bradley at right back.
Speaking to CasinoBeats, Hamann has suggested that the defender could return to Merseyside even if many fans despise him after he departed last summer.
“I would take Alexander-Arnold back. Whether he would contemplate it, I’m not sure. He wasn’t best pleased with the way people reacted when he said he wanted to go to Madrid. I was at the game against Madrid and saw the reception he got when he came out, but things can change quickly in football.
“It would take a lot of persuasion from Liverpool, I think. On his side, you don’t know what the reaction will be. But as a matter of fact, he was a tremendous player for the club, and he had the chance to go to Madrid. I never faulted him because the club could have extended his contract a year earlier had they paid him more money.
“If he wants to do something new then Real Madrid are one of the biggest if not the biggest club in the world, so I would take Trent back. The fans probably see it differently, but I think he’s a strong boy. Stranger things have happened in football, so I wouldn’t rule it out.”
The 27-year-old has missed Real Madrid's last 12 matches in all competitions, with a muscle issue ruling him out since early December. He is being slowly forced out the side and Liverpool may be tempted to try and bring him back in the summer if a deal can be reached.