I got this tidbit from Amazin Ave:
Butto was brought up as the 27th man so he's still limited by the rule that players that have been optioned must spend 15 days in the minors. The exception would be if they put another pitcher on the IL but a DFA does not create that exception. This DFA move is how they're adding Teheran to the 40-man roster.
So, Butto was usable in the double header but has to be sent back down. Getting sent down has nothing to do with his outing.
The DL spot for Megill was filled by Reed Garrett, because they needed a bullpen guy.
Garrett replaced Megill
and Teheran replaced Tonkin. (there's a Gulf of Tonkin joke in there somewhere, I just can't think of one)
I don't believe that being called up for the double header triggers the 15 day wait so Butto is available again for his next start in 5 days if they need him. The Mets have Garrett available as a bullpen arm for the next 3 games, figuring he gets a day or two off after his 3 inning performance, so he could be ready to go tonight if needed, certainly tomorrow, where as Butto as a starter would need 5 days rest.
All these rules make roster management feel like chess.
What was the worst off-season move the Mets did? Interestingly it could end up being the rule 5 guy the selected but didn't keep. The Mets like roster flexibility and have never been big on the Rule 5 picks, so they will often pick and trade. That's what the did last December with Justin Slaten.
The problem? Slaten looks like the real deal.
3 games, 3.2 innings, 1 hit. 0 walks, and good stats in the Spring as well. The Redsox are even using him in the closer role some. Granted, I don't think the Redsox are trying to win anything this year, but they seem to like him. It's early but Slaten looks like a keeper.
The mets got a guy who was drafted last year for $50,000, a college senior in 2023 who's not yet pitched in the minors. Ryan Ammons, who they can stash and wait a few years, see if he turns into anything. Still, I'd rather have Slaten. That would have been an interesting gamble and they could have just sent him back if the needed a roster spot, like they did with Darren O'Day some years ago, but that's another story.
Sorry if I write about this too much, but I enjoy the back of the roster moves. It can be affected by simple things like needing a spot starter for a day (and O'Day you might say), and it's mostly not anyone who makes a difference, occasionally it is.