Jed York supported the NFL making a change to what had become the most boring play in the sport.

But, as he explained after he cast one of just three “no” votes against the league’s kickoff proposal that was approved by NFL owners on Tuesday, the 49ers’ CEO wanted the league to have flexibility to make adjustments to the rule in the middle of the season.

Such a dramatic change could bring about unintended consequences, York said, and he wanted the NFL to be able to pivot with minor in-season adjustments.

As the rule was written, there is not allowed to be any changes until after the 2024 season.

“If there’s injury data or a competitive issue that doesn’t work, then it’s the asterisk season of the kickoff rule that didn’t work,” York said Tuesday at the NFL Annual Meeting. “I’m 100 percent for trying to make that play active in our game again.

“I think they put in a ton of time and a ton of effort to try to make something work. I’m just sure there are going to be tweaks to it, and I’d rather tweak it, if we have to, in the middle of the season, as opposed to ‘Here’s the asterisk season, and we’re going to tweak it at the end of the year.’ That’s it.”

The kickoff had mostly been legislated out of the NFL due to the high rate of injuries on the play.

The 49ers’ overtime loss to the Kansas City was the first game in Super Bowl history in which there were no kickoff returns. Twelve of the 13 touchbacks came on kickoffs out the back of the end zone.

The new kickoff rule, which easily passed a vote of league owners on Tuesday, begins with the kicker placing the ball on the tee at the 35-yard line. The point from which the ball is kicked into the play is virtually the only thing that remains unchanged from past seasons.

Now, the kicking team will set up with one foot on the receiving team’s 40-yard line. The receiving team will have at least nine players stationed between their own 30- and 35-yard line.

Those players will not be able to move until the kick touches the ground or a player inside the landing zone — defined as the goal line to the 20-yard line.

All kicks in the landing zone must be returned. Kicks that travel short of the landing zone will result in the receiving team taking over at the 40-yard line. A touchback that lands in the end zone will place the ball at the 30-yard line, while a touchback that skips from the landing zone into the end zone will result in the ball spotted at the 20-yard line.

“It’s interesting,” 49ers coach Kyle Shanahan said of the new rule. “I don’t think anyone totally knows. When you put guys in different spots, there’s different timing. It’ll be fun to watch. We’ll have to figure it out as we go. That’ll be a fun thing in the league but it will be different each week.”

The new rule, based on the XFL’s kickoff procedure, is designed to eliminate high-speed collisions on kickoff returns while also promoting more action.

“From a health and safety standpoint, we’ve tried to address the play because it was the highest injury-rate play that existed,” York said. “So they’re going from that to try to reintroduce the play to the game and make it more of a real play as opposed to a ceremonial play.

“I’m 100-percent for that. I just want to make sure with something that’s brand new, that we have the opportunity to address it during the middle of the season.”