While Rupinder will be unavailable for the tournament due to a hamstring injury, Uthappa had to return home to attend to a family emergency.
India is scheduled to take on Scotland in their first match tomorrow.
Rupinder will be replaced by defender Jasjit Singh Kular, who also doubles up as a dragflicker for the team.
Kular, who was a part of the 33-member core group that trained in SAI Bengaluru, has played 46 international matches for India with five goals against his name.
Sumit had a successful 2016 with the junior team, which won the Junior men's World Cup.
"With a strong core group who have been working together since February this year, we have several options and I don't see this as a setback for us at all," said coach Roelant Oltmans ahead of India's first encounter.