India will open their campaign against Scotland tomorrow.
The lead up to the opening encounter saw the Indian team led by midfielder Manpreet Singh win the practice match against England 3-1 on Tuesday with a successful dragflick by Harmanpreet Singh and a double goal by striker Mandeep Singh.
"To win this kind of tournaments we have to get a higher percentage of goals out of our opportunities and concede less unnecessary goals," Oltmans said.
The last time India played in London, the team created history by winning a silver medal at the FIH Champions Trophy.
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However, with ace dragflicker Rupinder Pal Singh and SK Uthappa ruled out of the tournament, India will bank heavily on the young Harmanpreet Singh to convert short corners.
"With a strong Core Group who have been working together since February this year, we have several options of strong players," stated Oltmans.
While Uthappa, who returned home for a family emergency, will be replaced by Sumit, defender Jasjit Singh Kular has been called in place of Rupinder Pal Singh who is being rested due to a minor injury.
The team's real challenge will be to get past an unpredictable Pakistan on June 18 before they face World No.4 The Netherlands on June 20.
"You always want to start well in the Pool Stage. Playing a Tournament like the Hero Hockey World League Semi Final (Men) is always challenging with a number of strong teams in the competition," Oltmans said.
"The Pools are equally strong too but based on the ranking in our Pool, we have to get a good start against Scotland," he added.