There are also question marks over winger Andik Vermansyah and defender Shahrom Kalam but coach Mehmet Durakovic welcomes Super League top scorer Paulo Rangel back into the side.
"We have almost half the team out, so we have to see who is fit to play," Durakovic told reporters at the Shah Alam Stadium yesterday.
"Guru is out probably the whole year. He will have an MRI (magnetic resonance imagine) scan and we will see what it shows.
"I hope it is not too bad because Guru has been fantastic. I feel sorry for him. He is one the best players we have.
"It's not been easy playing so many matches but we have a big squad and I hope those who come in will be able to do the job."
Shukur Jusoh or Hadi Yahya will fill in for Gurusamy while captain Bunyamin Umar could move into central defence if Shahrom is unavailable or Rizal Fahmi Rosid could come in.
Selangor will have to watch out for Group F's top scorer Nguyen Van Quyet, who scored the winner the last time the two teams met for his fifth goal of the competition.
"Hanoi have good foreign and local players," said Durakovic. "They have got qualify. We have to lift our standards.
"It was an unlucky mistake which cost us the game the last time and I hope to reverse that.
"We play every game to win and my philosophy is to play an attacking brand of football, so we will see where that takes us."
Hanoi manager Phan Thanh Hung said his team, who have the maximum nine points, have no injury or disciplinary concerns but expects a tough encounter.
"This match is important not just for us but for Selangor too as both teams can qualify for the next round," said Thanh Hung. By Devinder Singh
*Sumber Dari New Starits Times