The 8th Inning Pitching Change:
It took umpires a good 14 minutes to deliberate on a very simple and clear rule. Let's explain it.
Setting Up the Situation:
The Yankees, hosting a 4-1 lead going into the top of the 8th inning, had just used Wandy Peralta to get them out of a jam in the top of the 6th and then used him to get through the 7th. Both innings went fine with no additional runs coming across the board. However, regardless of how well he was pitching, pushing Wandy into a third inning of work would have been uncharacteristic. Since becoming a Yankee in 2021, he's pitched 2.0 innings just 3 times- each time starting both innings- and has never pitched in parts of 3 innings (or more than 2.0 innings). Needless to say, it was obvious the Yankees were going to go to another reliever.
The Yankees had the following options available out of the bullpen: (* indicates usage the day before; bold for typical high-leverage options)
Given the Yankees had a 3 run lead, and how both of their Top-2 relievers were used the night before, it looked to be a perfect situation to get some other innings from the bullpen. Thus, Aaron Boone & company decided that Miguel Castro would get the 8th. And it started just fine:
Yandy Diaz groundout
Harold Ramirez flyout
Manuel Margot double
and then Randy Arozarena was hit by a pitch that was high and in, setting up runners on first and second with 2 outs against a right-handed pitcher. This signaled a dead ball and came with an injury delay. After this happened, pitching coach Matt Blake went to the pitchers mound to talk with Miguel Castro about how they were going to approach Isaac Paredes.
After Matt Blake had his conference, Rays manager Kevin Cash signaled to the umpires that Ji-Man Choi was going to pinch-hit for Paredes. This became officially part of the game when the home plate umpire signaled to the official scorer. When this signal happened, Miguel Castro was alone on the mound and the Yankees coaches were all in the dugout.
Concurrently as this was happening, the Yankees took notice that the left-hand hitting Ji-Man Choi was warming up and they called the bullpen to get the left-handed pitcher Lucas Luetge warmed up. As they needed to stall for some time, Aaron Boone told catcher Kyle Higashioka to then go up to the mound to talk with Castro. During that catchers meeting, Aaron Boone then left the dugout- after wasting a good minute or two- to try and go up to make a pitching change to get Luetge into the game.
It was at this time that the umpires decided to meet and discuss if Aaron Boone was allowed to make a pitching change.
That deliberation took 14 minutes, including a call to the official umpire headquarters in Chelsea, for them to decide that Boone is in the right to make the change.
(Ultimately, Luetge allowed two straight bloop hits to Ji-Man Choi and then Rene Pinto, allowing 2 runs to score before getting the final out from a Brett Phillips flyout.)
What The Official MLB Rulebook Says:
(l) Visits to the Mound Requiring a Pitcher’s Removal From the Game A professional league shall adopt the following rule pertaining to the visit of the manager or coach to the pitcher:
(1) This rule limits the number of trips a manager or coach may make to any one pitcher in any one inning;
(2) A second trip to the same pitcher in the same inning will cause this pitcher’s automatic removal from the game;
(3) The manager or coach is prohibited from making a second visit to the mound while the same batter is at bat, but
(4) if a pinch-hitter is substituted for this batter, the manager or coach may make a second visit to the mound, but must remove the pitcher from the game.
A manager or coach is considered to have concluded his visit to the mound when he leaves the 18-foot circle surrounding the pitcher’s rubber.
Were The Yankees in the Right?
As per the rules, the Yankees used a mound visit when Matt Blake went to talk with Miguel Castro after the Randy Arozarena HBP. That was dead time.
Matt Blake then was firmly situated in the dugout when the umpire signaled to the official scorer that Ji-Man Choi was now a part of the game. Kevin Cash could've told the umpire while Matt Blake was still on the mound (though, to be fair he didn't), but up until the umpire signals to the official caller about the substitution then it hasn't become official. By the time that happened, the only Yankees on the field were the players.
The Ji-Man Choi substitution allowed the Yankees to make a pitching change (provided the pitcher reached the 3-batter minimum) as per section 4 of rule 5.10. Aaron Boone was within his right to head to the mound to remove Castro from the game at that point.
That's it. It's a very simple rule to understand.
How it took a group of 4 professional umpires 14 minutes of discussing to figure that out is telling.