Rooney rushed over to Foy to complain after a controversial tackle by Vincent Kompany on Nani in the 12th minute of the game, after which the City captain was shown a straight red card.
"I didn't wave any imaginary card," Rooney told The Sun.
"I clearly pointed out, and a few other players did as well, that it was a two-footed tackle. It was down to the ref to send him off.
"As professional footballers, when you leave the ground and go in two-footed we've now been told by the referees it's a red card. Refs come and see us before the season starts. I felt Kompany had done that."
City boss Roberto Mancini had previously accused Rooney of influencing Foy's decision.