The centre was a healthy scratch Monday night when the Toronto Maple Leafs hosted the New York Islanders.
Kadri apologized to his teammates and coaches for being 20 minutes late to the team's practice facility and took responsibility for his mistake.
"I've never, ever had this happen in my career where I've missed a meeting and been sent home," Kadri said after Monday's morning skate at Air Canada Centre. "It's uncharacteristic and something that's never going to happen again."
Interim coach Peter Horachek brought up Kadri's "past" as something he talked to the 24-year-old centre about when telling him he'd be scratched against the Islanders. Horachek refused to elaborate any more about what in Kadri's past led to this decision.
When Kadri was with the AHL's Toronto Marlies, he was also punished for missing a team meeting.
Winger Joffrey Lupul, whose locker stall is next to Kadri's, brushed off the mistake as something that happens on occasion in sports and life.
"If I wanted to talk about every time I screwed up when I was 23 or 24 I'd miss lunch talking to you guys," Lupul said with a laugh. "It's important he learns from it.
"Obviously, it's not a joke, it's serious stuff, but it's over. It's not like anyone's going to hold any ill will in here."
Zach Sill moved over to centre and Brandon Kozun returned to the lineup in Kadri's absence, Horachek said. The other change for the Leafs was defenceman Petter Granberg coming up from the minors to replace Roman Polak, who is scheduled for season-ending hernia surgery.
Though Polak had been dealing with groin problems for quite some time, his immediate absence was a surprise. Kadri's was not, especially after Horachek said Sunday he'd be available to play "if I want him."
Islanders captain John Tavares, Kadri's former teammate and roommate with the OHL's London Knights, praised the Leafs forward for his handling of the situation.
"I think he's already responded really well to obviously maybe a lapse in judgment," Tavares said. "He's a guy that is very focused and committed.
"It happens, I'm sure. Obviously it's not what you want to happen, I think you always want to be on time and be professional and count on yourself the right way. He was always that way in London."
Tavares said he was late once during his rookie season, arriving at the rink at 9:32 a.m. when players had to report at 9:30. Veterans, he said, set him straight.
Horachek is enforcing a team rule in sitting Kadri.
"There's rules that you have to abide by, and there's different circumstances, different situations," said Horachek, who at one point bristled at the continuing line of questioning about Kadri. "I'm over it now. There's no sense dwelling.
Kadri, Toronto's fourth-leading scorer with 36 points, understands the situation.
"It's a team rule and team rules can't be broken and I'm the first guy to stand by that," Kadri said. "I just made a mistake and I'm willing to live with the consequence."
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