The Partenopei suffered a shock result at the hands of the Czech side in the Europa League midweek, and the Slovak concedes the manner of the loss was inexcusable
The Partenopei have a mountain to climb if they are to progress to the round of 16 in the continent's secondary tournament after conceding three away goals without reply at the San Paolo earlier in the week.
However, they have the chance to make amends for their surprise reverse to the Czechs with a positive result against Sampdoria on Saturday, and the Slovakia international is desperate to restore fan confidence.
"We felt a bit ashamed. It went horribly wrong and our fans did not deserve that," Hamsik wrote on his official website.
"I had a chance to equalise early in the second half but didn't take it. [If I scored], it would have ended differently. However, I did not find the space.
"We need to think about the game with Sampdoria, and we must do so immediately because the match against Viktoria Plzen has ended."