Aguero is struggling with a foot injury.
"During the match against Chelsea, I injured my ankle and it was sprayed with a topical anaesthetic that caused a burn on the upper part of my right foot," said Aguero, on his official website.
"The injury worsened after a few days and when boils appeared I was told I wouldn't play against Stoke and then against Sunderland.
"You can imagine how I felt, being out of playing condition when my team is trying to take the championship. It's always worse from the bench.
"After that I started receiving incredible rumours about how it all happened.
"I know my life is very public and I'm willing to take criticism even if I disagree with it. but I will not sit quietly while lies are being spread - even more so if they cast doubt upon my professionalism.
"This is a simple injury and not a plot of intrigue."