Danijel Subasic (Supplied)
Subasic has been the focus of frenzied media attention since he saved three Denmark penalties in a shootout on Sunday to ensure Croatia's place in the quarter-finals in Russia.
On most of the photos in the Croatian press he is seen in a T-shirt he wears under his jersey, featuring a portrait of Hrvoje Custic under the caption "Forever".
The two played together for their hometown team NK Zadar when in 2008 Custic tragically hit his head on a concrete wall surrounding the pitch during a First Division match. He died a few days later.
Subasic, 33, always plays in a T-shirt with Custic's image under his jersey, sometimes with the caption "Where are you, my angel?"
"My Hrvoje will always be with me, and not only on a T-shirt but also in my heart," Subasic said before the World Cup in Russia.
Subasic remained modest about his performance on Sunday.
"Penalties are a lottery, this time luck was on our side," the Monaco goalkeeper told the press.
NK Zadar were also the first team of Croatia captain Luka Modric and the two played there together.
"These are all ... kids of Zadar and our club. I cannot be more proud," Svetko Custic, the father of Hrvoje Custic and NK Zadar director, said after the win against Denmark.
Croatia play against hosts Russia on Saturday in Sochi.