The Bears confirmed the procedure in a statement Monday, adding the surgery was successful and Miller will remain in the hospital for evaluation.
Miller, 33, suffered a gruesome knee injury in the third quarter when attempting to make a touchdown reception. The dislocation of his knee was apparent on the field, and he needed an extended period of medical attention before being carted off the field.
Bears head coach John Fox confirmed to reporters he spoke with Miller and that the tight end is in "good spirits."
"He pretty much wanted his touchdown back," Fox said when updating Miller's condition.
Mortensen later reported Miller is undergoing an MRI after the surgery to "evaluate blood flow and anatomy" of the injured leg.
"Zach means a lot to this team beyond the X's and O's and what he brings to the field but what he brings to us as a person," Bears quarterback Mitchell Trubisky told reporters. "Specifically how much he has helped me grow in this process. You never want to see a teammate go down like that."
Miller recorded 20 receptions for 236 yards and two touchdowns through the Bears' first eight games of the season. He is second behind only Tarik Cohen for the most targets on the team with 35.
In his third season with the Bears, Miller has had a career plagued by injuries. He did not record a single offensive stat from 2012 to 2014 due in part to injuries, and he has never played in a full 16-game season. In 2016, he set a career high with 47 receptions for 486 yards but was limited to 10 games due to a broken foot.