Al Amerat (Muscat), Oct 17 : Oman cricket team coach Duleep Mendis has said ahead of the ICC T20 World Cup First Round, Group B opener against Papua New Guinea (PNG) later on Sunday that he has seen a vast improvement in the mental aspect of his side since he took over, but his boys are still "not hard enough" to play Test nations. "We have to do well to go forward, but they (team) have the ability to do so. One thing I felt was lacking was the mental side. I worked on that, and to a certain extent I think it has worked. We have put them (the boys) through a lot of exercises and they have come out of them. Still when we play against a Test nation I feel they are not hard enough. But it will come," said the Sri Lankan cricketing legend. Oman first appeared in an ICC men's T20 World five years ago; the most recent edition of the tournament. It was a successful campaign for the first-timers, who won one of their three matches. This time around, they'll have bigger ambitions. The nation ranked 18th in the world on the ICC T20I team rankings will be eyeing a spot in the Super 12 stage with two qualification places up for grabs in each of the 'First Round' groups. They won't have to look far for motivation either as they are spurred on by home support. PNG go into the tournament opener full of confidence, ranked three places higher than their opponents. And with fixtures against Scotland and Bangladesh to come, this match could well determine the World Cup fate of both nations. The PNG squad are the first group of players to represent the country at a men's World Cup, 48 years after the nation was named as an associate member by the ICC. They came close in 2013 and 2015, losing late in the qualification process. But there was no such heartbreak this time around, with the team sealing their spot in the tournament. But the East Asia-Pacific qualifiers have had to wait for their World Cup debut, with the pandemic meaning there has been two years between that qualifying celebration in Dubai and Sunday's opening match against Oman. Oman aren't exactly World Cup old-timers themselves, with this tournament being only the country's second appearance at a Men's T20 World Cup. But, the 2021 tournament has an extra-special edge for the nation due to their role as co-hosts. For the opening week, all Group B matches in the first round will be held at the Al Amerat Cricket Stadium, giving Oman home advantage in their bid to face off with the best in the world. Possible Oman playing XI: Jatinder Singh, Aqib Ilyas, Ayaan Khan, Zeeshan Maqsood, Mohammad Nadeem, Sandeep Goud, Naseem Khushi, Kaleemullah, Khawar Ali, Fayyaz Butt, Bilal Khan Possible Papua New Guinea playing XI: Assad Vala, Tony Ura, Charles Amini, Sese Bau, Norman Vanua, Simon Atai, Kiplin Doriga, Jason Kila, Nosaina Pokana, Damien Ravu, Chad Soper. /IANS