The Gunners' 28-match unbeaten run was ended by a 3-1 Champions League reverse in Seville on Tuesday after Arsene Wenger rested most of his first-choice players.
But Toure insisted: "Our confidence will not be affected by one poor result.
"The run is over so now we will just start all over again.
"We just need to show the character and the desire we have displayed all season and play as we know we can do.
"We knew a defeat would come one day but we didn't know when it would be.
"But to be winners you need to get over these setbacks and show courage."