Sandy Alderson meets with Mets catchers Friday to offer new instructions on blocking the plate.PORT ST. LUCIE, Fla. -- Sandy Alderson met with Mets catchers on Friday morning, trying to explain the new ban on blocking the plate that may, or may not, go into effect at the MLB level in 2014.

The bottom line: Alderson wants Mets catchers to allow runners a lane to the plate, whether the new MLB rule is in effect in 2014, postponed or shelved entirely.

Travis d'Arnaud said he was instructed Friday to stand completely in fair territory, with his left foot at the inner corner of the plate, and give the runner "pretty much the whole plate."

The logic: There is no sense exposing Mets players to injury risk by having them block the plate entirely, according to Alderson, who is the chairman of the rules committee.

It will run counter to d'Arnaud's instincts.

Travis d'Arnaud will need to fight his natural instinct to block the plate.

"I know a lot of catchers love that play at the plate, just like I do," d'Arnaud said. "... It's part of being a catcher. Say, for example, it's Game 6 of the World Series, and I'm told I can't block the plate. Well, my instincts are going to tell me to save that run being scored. That's part of the game that every catcher enjoys. It's like our thrill, like the infielder making a diving play in the hole and throwing someone out from his knees."

The Mets had been encouraging d'Arnaud last year to avoid collisions anyway to try to keep him healthy.

"It was actually funny, because during spring [training] last year, I had a play at the plate where I blocked it," d'Arnaud said. "... I worked on it after that a lot more and made the adjustments I needed to make."

Alderson said the rule may be postponed a year. It still may be tinkered with somewhat even if it is enacted for this season because the Players' Association and MLB are still discussing the final language. He added that the rule may be different in the majors and minors.

"I think you'll see our guys practicing assuming that we want to try to avoid collisions at the plate," Alderson said Friday, a day after meeting with MLB's Joe Torre and Tony La Russa about the matter.

On support for avoiding collisions, Alderson added: "I think that's the prevailing sentiment among major-league front offices and managers. I can't speak for the players."

Alderson said Mets catchers were "receptive" to Friday's explanation from him.

"You can't expect guys who have been playing professional ball for a few years, part of whose job description is to take the hit at the plate, to come up to you and say, 'Hey, I don't want to take the hit anymore,'" Alderson said. "I think it's unrealistic to expect that players are going to volunteer that. On the other hand, if you talk to former catchers, there are maybe one or two who voiced a different opinion, but the ones that I've talked to, or who have reached out to me, more or less to a man they think that it's in the best interests of catching and the game as well to change the rule.

"We know more about concussions and so forth now than we knew 10 or 15 years ago. And I think we have to think about that. I'd rather be proactive than reactive myself."

Basically, Alderson explained, whatever rule is enacted will require the catcher to give some lane to the runner.

"The basic idea is if you're going to require the runners to slide, you have to give them a lane to the plate," Alderson said. "I think that's the basic premise. Now, if a ball takes you into the lane, or causes a situation that's unavoidable, then you've got a situation that's unavoidable. But the point of the rule is in all circumstances, the runner would have to slide. That's the college rule. That's the high school rule. Probably if you play tee ball today, that's the rule."

Managers, under the new video review, will be able to challenge whether a lane to the plate is provided to the runner.

"Again, it's going to depend on the final rule, but it could be challenged on the basis of safe or out," Alderson said. "It could be challenged on basis of whether the runner acted appropriately. And it could be challenged on the basis of whether the catcher acted appropriately. All go to safe or out.

"And the second level of review would be: Was this egregious enough for the player to be ejected? And then, I guess, subsequent to that, postgame, as in say the NFL, it would be reviewable to determine whether there would be additional fines or suspensions."

• On instant replay, Alderson said the Mets have not yet set up their process for challenges, including who in the clubhouse area might review the play and advise Terry Collins. The GM said he first wanted to hear Thursday's explanation from MLB officials of the logistics.

Alderson acknowledged teams may stall to have clarity about whether they would prevail before asking for a video review.

"There's nothing definitive. There's nothing that says you've got to challenge within 30 seconds or what have you," Alderson said. "There are some other demarcations, like: Is the pitcher on the rubber? Is the batter in the box? That kind of thing. So I think there's going to be a lot of umpire discretion involved. But, look, if there's a potentially challengeable play, and you're trying to figure out whether to challenge or not, is the manager going to go out and beef? Probably. Is the manager going to go out and ask for the umpires to get together and have a conference? Maybe. Is the batter going to get dust in his eyes? Maybe.

"Who knows how this is all going to work out and how the gamesmanship may be? Which is why the whole issue of pace of game and length of game, I think, is still up in the air. We'll see how it gets applied."