TORONTO -- Domingo Germán watched with angst as the four umpires conferred near Rogers Centre’s first-base line on Tuesday night, and it was not a good sign when their chat ended quickly. An unacceptable sticky residue had been discovered on the Yankees right-hander’s palm, confirming that he had thrown his final pitch of an abbreviated evening.

Exactly what the substance was remains up for debate. Speaking after the Yankees’ 6-3 win over the Blue Jays, Germán insisted that he had used only the rosin bag, which is available at the back of the mound. Crew chief James Hoye disputed that in the strongest terms, saying it was “definitely not rosin,” and that “this was sticky, as in my fingers had a hard time coming off his palm.”

Either way, Germán faces an automatic 10-game suspension, which puts the Yankees in a bind -- they cannot replace him on the active roster.

"I’ve got to apologize to my teammates and my team,” Germán said through an interpreter. “I'm putting them in a tough position right now. Understanding how much the bullpen has been used, and what my plan was for tonight to pitch, and putting them in a tough situation where I'm not pitching out there anymore."

Germán had been one of the Yankees’ top starters this month; he departed with a 1.64 ERA across four May starts after having posted a 5.54 ERA in five April starts.

“It’s a tough spot. He was pitching great,” said Yankees captain Aaron Judge. “It’s something that we’ll definitely talk about over the next couple of days. I think quite a few people have been in his ear about it.”

On this night, Germán had pitched three perfect innings and he was returning to the mound to begin the fourth when first-base umpire D.J. Reyburn intercepted him. According to Hoye, Reyburn had inspected Germán after the first inning and planned to see him again after the third, but he had missed him. Reyburn waited until the bottom of the fourth, when he discovered the sticky substance.

“His hand was clearly shiny on the palm and his fingertips, and it was extremely sticky,” Hoye said. “So [Reyburn] called me over and said, 'Hey, take a look at this.' And the instant I looked at his hand, it was extremely shiny, and extremely sticky. It's the stickiest hand I've ever felt, and same with DJ.

“And so at that point, we brought over John Libka, the second-base umpire, and [third-base umpire] Clint Vondrak, to verify all four of us had the same opinion. We all had the same opinion: shiny, extremely sticky and it's the worst hand we've ever felt during a game.”

After the ejection, Judge said that first baseman Anthony Rizzo and pitcher Gerrit Cole touched Germán’s hand to “see what was going on there.” Television replays also appeared to show a dark substance on Germán’s pants, near his right hip; Germán claimed it was chewing tobacco.

“Ultimately, that’s Domingo’s responsibility to make sure we’re in a better position there,” Yankees manager Aaron Boone said. “I think they’ve all experienced this enough and what it is to be a pitcher, what the differences are. The reality is, we should all have a very good idea about what the line is. Apparently, Domingo crossed it tonight.”

This is Germán’s second brush with "sticky stuff" enforcement this season; as Boone said, “He’s been in the crosshairs a little bit.” On April 15 against the Twins, Germán had retired the first 16 Twins he faced when he was inspected by the same umpiring crew, who determined that Germán had too much rosin on his pitching hand.

The umpires wondered why Germán’s hand was sticky or tacky even though he had hardly used the rosin bag on the mound; Germán had explained that he liked to use a rosin rock in the dugout between innings. That day, Hoye told him to wash off the excess rosin. Germán was allowed to remain in the game, a decision that subsequently prompted the ejection of Twins manager Rocco Baldelli.

"I don't want this to happen again,” Germán said. “I [followed] the instructions; I'm not using it enough. Now, I use it too much, and there was a problem because it was too much on my hand. So, summer is coming; we're going to be sweating a lot out there. You need the grip, right? But you also want clear direction from [the umpires] to see what's appropriate and what's too much."