This will be Englishman Constantine's first competitive assignment since being appointed India coach for the second time in his career.
India are currently ranked a lowly 171 in the FIFA rankings, while the Himalayan nation is placed nine places below at 180.
"If the players are willing to work hard, results can always be achieved," Constantine said at the pre-match press conference.
"This may be a sentimental match for me as I had earlier coached Nepal. But on the pitch it would be pure business. Nepal are an organised side and would be ready to fight. It will be a big challenge," Constantine added.
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The last time the two sides locked horns, in November 2013, India had won 2-0 in an international friendly held at the Kanchenjunga Stadium in Siliguri.
That game saw Chhetri surpass former captain Bhaichung Bhutia as India's leading goal scorer at international level, and the Delhi boy would look dish out another impressive performance at the Indira Gandhi Athletic Stadium tomorrow.
On appointing Paul as captain, the former Rwanda national coach stated that the skipper must reflect the personality of the team.
"It doesn't make a difference. We need to first have a look at the players. The captain has to reflect the personality of the coach and will be of my choice," he had said.
Paul plied his trade for Mumbai City FC in the inaugural edition of the Indian Super League (ISL) and currently plays for Salgaocar FC where he has impressed this season.