The England defender is battling to overcome a form slump, though isn't alone at Liverpool in his struggles so far this season.
The defending Premier League champions sit in fifth place on the table, seven points behind leaders Manchester United, which knocked them out of the FA Cup on Sunday. The Reds now have the Premier League and Champions League titles to compete for this season.
Alexander-Arnold has battled to reach the heights of past campaigns this term, but Hamann insists it is to be expected for a player still in the early stages of his career.
Former Reds midfielder Hamann told Stadium Astro via Fotboll Transfers: "The only thing that surprises me is that the slump did not come earlier.
"If you play weekly or every third day, the standard he set has been exceptional. He has been flawless for two years and played over 100 games. I find the criticism of him ridiculous.
"To criticise a player who is still very young because he has had some half-baked appearances and not done any assists in a few months is ridiculous."
While he's battling to find some form, Alexander-Arnold has remained a first-choice selection for manager Jurgen Klopp this season. He's managed 22 appearances in all competitions so far this term, including four assists.
- updated January 27