The Brazil star said he respected manager Roberto Mancini's decision and vowed to prove he is worthy of inclusion in the team for next week's decisive return leg at Old Trafford.
"The Carling Cup is our first big chance for a trophy," Robinho told the Mirror. "For me, it will be very hard not to play in the return leg against United.
"I wanted to play in the first game but the coach decided against it. It was a great game and these matches are always special.
"City have a 2-1 advantage from the first game but matches at Old Trafford are always difficult."