According to the NHL's Department of Player Safety, Lucic has been suspended for one game due to hitting "an unsuspecting opponent."
The play in question occurred about midway through the third period of Arizona's 3-2 victory on Saturday.
The Kings were attacking in Arizona territory, getting a shot to the net that was stopped by Coyotes goalie Louis Domingue.
Connauton appeared to use his stick to slash Lucic, which caused Los Angeles' star to respond by skating over to him and throw a right jab at the 25-year-old's head.
Officials immediately intervened and assessed Lucic a roughing minor and game misconduct that led to his ejection.
Speaking to reporters after the game, per Jon Rosen of L.A. Kings Insider, Lucic explained why he reacted as strongly as he did to the situation.
"Well my whole hand went numb," Lucic said. "I truly thought of the worst because I couldn’t feel my hand after the slash like that, and that’s the way I reacted the way that I did. Luckily we didn’t go four-on-four, we still had the power play, but you know, like I said, I’m just thankful that everything came back negative."
Lucic's actions, while certainly a heat-of-the-moment response, will cost the Kings one of their most valuable weapons during Sunday's showdown against the San Jose Sharks. He ranks fourth on the team in goals and points.
The Kings have built a comfortable eight-point cushion in the Pacific Division, so Lucic's brief absence won't derail their season, but the Sharks are building momentum, with two consecutive wins heading into play on Sunday.