New Delhi, Apr 4: Indian boxers, including former world number one Vijender Singh, will seek to grab the last available slots for London Olympics, but will have to fight it out against a stellar field of over 130 competitors from 27 countries when the Asian Qualifying tournament starts in Astana, Kazakhstan on Thursday.

Instructed to be at their aggressive best during the event, which would decide 25 Asian slots for the Olympics, the boxers will kick off their campaign tomorrow evening after the draw is settled in the afternoon the same day.

India has already bagged four slots -- L Devendro Singh (49kg), Jai Bhagwan (60kg), Manoj Kumar (64kg) and Vikas Krishan (69kg) -- during the first Olympic Qualifiers (last year's World Championships in Azerbaijan).

After more than three months of training in Patiala, six Indians are ready for a shot at Olympic qualification and given the new scoring system, under which points earned are shown only after the end of a round instead of live updates, national coach Gurbax Singh Sandhu said it is imperative that his boys are seen to be the more aggressive ones by the judges.

"They have been told to do away with the closed guard and land as many punches as possible to ensure that judges can see the aggression. Now it is all about the rate at which you land punches because the bouts have become very high scoring," Sandhu had said before the team's departure for Astana.

"The boys have also been told not to back-paddle too much as that is perceived to be a defensive tactic. They should not keep a shell guard. But as and when the situation demands, they should be able to adjust," he said.

Talking about India's prospects in the tournament, the team's Cuban coach Blas Iglesias Fernandes said at least two should book London berths.

"I am expecting a minimum of two, that would make it a very happy situation. If we come back with three, that would be just brilliant," said the bespectacled Cuban, who has been with the Indian boxers for more than a decade.

Among the boxers who are going for the Qualifiers is Olympic and World Championships bronze-medallist Vijender, who lost in the opening round of his first bid to qualify for London. But with his middleweight category (75kg) having four slots up for grabs, he is likely to make the cut this time.

"The situation is similar to 2008 when I had failed to qualify in the first two attempts. At that time too, I made the cut through the Asian Qualifiers. There were only two slots available in my weight category at that time. I won gold at that time. This time there are four slots so the task is easier," Vijender has said.

Uzbekistan's two-time AIBA World Champion Abbos Atoyev, Thailand's Athens Olympic Champion Manus Boonjumnong, China's former Asian Champion Zhang Jianting, Turkmenistan's Youth Olympic Games bronze medallist Nursahat Pazziyev and Iran's two-time Asian Games bronze medallist Mohammad Sattarpour will be among the challengers Vijender will face at the event.

Another four slots are there to be taken in the 52kg, in which the Indian challenge would be presented by Suranjoy Singh, who has been keeping a low profile after a prolific 2010 in which he won seven gold medals.

Three slots each are there to be taken in both the 56kg and 81kg divisions. Two promising teenagers -- Shiva Thapa (56kg) and Sumit Sangwan (81kg) -- would not just have to make the semifinals but may have to fight it out in a play off bout to book their London tickets.

"It is the biggest chance of my life and I am going to give my 200 per cent. It's a dream that I have waited to live and finally it's here. I will keep myself calm and just focus on giving it my all," said the 18-year-old Shiva.

The 19-year-old Sumit was bubbling with similar enthusiasm and claimed to be in the peak of his form.

"I beat an established boxer like Olympian Dinesh Kumar in the trials and I can say with confidence that I am on a high. My form and fitness is at its best," said the imposing counter-puncher, who feels his height would work to his advantage in a heavy weight category.

Asian Games silver medallist Manpreet Singh and Commonwealth Games gold-medallist Paramjeet Samota will vie for the one slot each available in the 91kg and the +91kg, respectively.

The Team: Suranjoy S Mayengbam (52kg), Shiva Thapa (56kg), Vijender Singh (75kg), Sumit Sangwan (81kg), Manpreet Singh (91kg), Paramjeet Samota (+91kg).

Support Staff: Gurbax S Sandhu (Coach), Blas Iglesias Fernandez (Coach), Kuttappa C Achaiah (Coach), Jaydev Bisht (Coach), Brig PK Muralidharan Raja (Team Manager), Hari Varma ( Physiotherapist), Abhishek Chowdhery (Doctor).

PTI