When a collision knocked off Mike Smith's mask, the Arizona Coyotes goaltender was less than pleased upon being told a few minutes later he had to leave the game.

One of the NHL's central spotters in New York made that call to trainer Jason Serbus, and in accordance with the league's concussion protocol, Smith's departure was mandatory.

''Mike didn't want to come out, but that's what was going to be done,'' coach Dave Tippett said. ''I'm interested to see how that one goes in an overtime in playoffs or something like that. We'll see how teams react to that one.''

The playoffs are still a month away, and teams already are not reacting well to concussion protocol for goalies, which is why it's one of the topics that general managers are expected to discuss at their annual March meeting beginning Monday in Boca Raton, Florida. Smith and New York Rangers goaltender Henrik Lundqvist are among those who have been critical of the rule.

Other issues as GMs try to refine rules they've put in place in recent years include the offside rule, coaches' challenges, goalie equipment and goalie emergencies.

Video review is among the hottest topics, especially the time it takes. Major League Baseball recently instituted timing guidelines for umpires, and that could soon happen for hockey officials.

''That's probably maybe the No. 1 discussion,'' Dallas Stars GM Jim Nill said via phone Sunday. ''Other than getting the call right, it is the time frame. It's something we can't go seven, 10, 12 minutes to get it right. ... It is something where I think the call has to be done within a certain time frame to keep the game going.''

GMs also will discuss some controversial coach's challenges where a player's skate is off the ice and the play is ruled offside. It came up during a playoff series last year between the Chicago Blackhawks and St. Louis Blues and has been a subject of discussion at previous meetings.

Updates to the league's concussion protocol will be under the microscope after Smith and Lundqvist blasted the system as flawed. Connor McDavid and other skaters have expressed concerns that the rules could have a major impact come playoff time - and goalies are at the center of the debate.

''If there is an instance that takes place where you think there is a possible concussion, I think we need to look after that,'' Nill said. ''When you do that, there's a risk of a player coming in cold. I guess the answer to that for me sometimes, it's no different than if a goalie hurts his knee, he's coming out and the other guy's coming in cold.''

Goalie equipment and emergencies - where teams have to sign players to tryout contracts to back up for a game - are also on the agenda. After missing the past two meetings, George McPhee will attend as GM of the Vegas Golden Knights for the first time; owner Bill Foley's final expansion payment went through last week.

GMs said criteria for the June 21 expansion draft have been made clear, so there's no need for further clarification. Blind-side hits, which were discussed at the November meeting, and playoff formats aren't on the official agenda but may be brought up over the course of the three-day meeting.

Ken Holland of the Detroit Red Wings has suggested expanding the playoffs to nine or 10 teams in each conference with play-in games similar to MLB, and the strength of the Metropolitan Division this season - where the fourth-place team has more points than the Atlantic Division leader - has generated some questions.

''I don't know that they want to keep changing it, but this has got to be an impetus for at least a discussion when something happens like this where there's so many good teams in the one division,'' said Brian MacLellan of the league-leading Washington Capitals, who acknowledged it would be self-serving to propose a change.

Copyright © 2017 Score Media Ventures Inc. All rights reserved. Certain content reproduced under license.