Valon Behrami says Victor Obinna is already a key player at West Ham United.
The Nigeria international has been a revelation since arriving on-loan from Inter Milan.
Swiss star Behrami, 25, said: "It'll be a tough game but we've done well against Arsenal in the last couple of seasons.
"If we keep going like we did in the second half and extra-time against Stoke then I'm sure we can get a good result, especially if Victor plays.
"Everyone will fear playing him one against one. He's unbelievable and can score every time he gets a chance."