Del Piero led an unbeaten Juve to their 28th Serie A title this season, with this weekend's cup final set to be his last game for the Italian club after 19 years playing for the Bianconeri.
Hamsik admitted winning the cup would be a huge boost after Napoli narrowly missed out on qualifying for the Champions League to Udinese, but reserved his praise for the 37-year-old Del Piero, whom one day he hopes to emulate.
"Del Piero is a phenomenon," Hamsik told Corriere dello Sport.
"He has made history at Juventus over the past 19 years with loads of victories. I don't like the use of superlatives, but we are talking about a truly extraordinary player, who still is very strong.
"I would very much like to become Napoli's Del Piero. It would be a source of pride for me to still be a key player of this team by 2016, even though it does make me feel old to look that far ahead."
Victory tomorrow for Napoli would be their fourth cup triumph and their first silverware in 22 years since their last Serie A title win in 1990, whereas if Juve lift the cup it would complete their third domestic league and cup double.
Juve will be without centre-back Giorgio Chiellini for the final after he was substituted with just two minutes left of Juve's 3-1 win over Atalanta last Sunday.
Juventus coach Antonio Conte revealed he did not know the full extent of Chiellini's injuries, but he would definitely play no part against Napoli.
"It was a thigh twinge," Conte said. "He will certainly be out of the Coppa Italia final, but needs more tests."
Midfielder Andrea Pirlo believes more silverware is on the cards for Juve this season, although he expects a tough encounter against Napoli.
"On Sunday we'll show the right concentration and desire to lift this trophy," Pirlo told Sky Sports.
"We've laid the foundations to do something great.
"When you start to achieve success, you want to get more. We'll have the chance to lift further cups and trophies and to play more finals. We can definitely win more silverware.
"Napoli are a great side, they've showed their value over recent years, and will certainly give their all. It will be a tough match."