"When you think that you know what the right decision is, you have to act on it," Shanahan told the gathered media Wednesday, per TSN. "I think that waiting at this point would have been the wrong thing."
Shanahan brought Babcock to Toronto in May 2015, signing him to an eight-year, $50-million deal. Despite finding regular-season success, the Maple Leafs were unable to escape the first round of the playoffs in each of the last three campaigns. The team's slow start this year sealed Babcock's fate.
"(General manager) Kyle (Dubas) and I are in constant communication. I think that it really just came down to the last couple of weeks," Shanahan added. "We spoke in the last 48 hours again, and I just felt that it was something that needed to be done, and Kyle felt the same way."
The Maple Leafs have lost their last six games and sit in fifth place in the Atlantic Division with a 9-10-4 record.
"Our game is not really meeting our expectations," Shanahan continued. "We're mistake-prone on defense, the attention to details aren't there. Even the explosive offense our team was known for has been missing for a while now."
Sheldon Keefe will take over as the Leafs' new head coach. The 39-year-old has served as head coach of the AHL's Toronto Marlies since 2015, leading them to a Calder Cup title in 2018 and an overall record of 199-89-22-9.