Myneni lost 2-6 1-6 to seventh seed Briton Liam Broady in just 62 minutes in the opening round match of the USD 50,000 hard court event.
Broady was dominant in the contest as he never faced a breakpoint and broke Myneni five times in the match.
Meanwhile, Yuki was locked 4-4 with Croatian qualifier Matija Ecotic in the opening set when rain halted the match.
The match will be completed later today.
In the doubles, Myneni and Ramkumar have already reached the quarterfinals with their respective partners. Myneni and Bulgaria's Dimitar Kutrovsky knocked out the top seeded Australian pair of Alex Bolt and Andrew Whittington 7-5 5-7 10-7 in their opening round.
Ramkumar and his Australian partner John Millman routed American wild cards Sam Barnett and Jesse Witten 6-0 6-0.