He was suspended and given an undisclosed fine by Major League Baseball for "inappropriate actions" during Friday's game against the Cardinals.
Contreras threw down his catcher's mask moments after Cubs pitcher John Lackey was ejected in the fifth inning for arguing with umpire Jordan Baker. The mask made contact with Baker's leg, and Contreras also was ejected after confronting Baker.
Contreras said Friday that his intention was not to hit anyone.
"I apologize to everybody, to the fans, to MLB, to the umpire," Contreras said then. "I'm sure if I see Jordan tomorrow I will apologize to him."
Cubs manager Joe Maddon said Contreras needs to try to curb his emotions "a little bit," but he was glad the situation was resolved.
"It's good news," he said Sunday. "We'll have the one game over with and move it on from there. Get it off his mind and play it forward."
MLB also fined Lackey an undisclosed amount for his actions.
With two on and two out in the top of the fifth inning and a 2-2 count on Cardinals pitcher Carlos Martinez, Lackey threw a slider that looked to be a strike. Even Martinez began to walk back to the dugout, but Baker called it a ball, setting Lackey off.
After a few harsh words, Lackey returned to the mound, and his 3-2 pitch was hit into center field for a run-scoring single.
As Lackey ran to back up home plate, he screamed in Baker's face, getting kicked out in the process.
ESPN's Jesse Rogers contributed to this report.