SEATTLE — The numbers are striking.

Gary Sanchez became the first Yankee in franchise history — and third player in MLB history — to hit eight homers in his first 19 games when he went deep twice more in Monday’s 7-5 loss to the Mariners.

The 23-year-old catcher was on a 14-for-25 tear with six homers, two doubles nine RBIs and four walks in his last seven games entering Tuesday.

“It’s unbelievable,” Starlin Castro said. “He’s Babe Ruth right now. Nobody can get that guy out, and when he gets an out, it’s a line drive. It’s really fun to watch. He’s a great catcher, too. Nobody can run on him.”

That’s almost true. Sanchez has thrown out five of seven would-be base stealers, well above the 40 percent clip he averaged in the minors. The two successful stolen bases came with Dellin Betances on the mound, and for all his strengths, the Yankees closer is notoriously bad at holding runners on.

The numbers, for now, are overwhelming, but Mark Teixeira, in the final weeks of his career, doesn’t need stats to know what he’s seeing.

“It’s almost like it’s easier for him here,” Teixeira said of Sanchez. “He’s more focused. He’s got more energy. He’s hitting balls further. You don’t see that very much. You don’t see guys come up here and make the game look easy in the big leagues in your first couple of weeks and he’s doing that. It’s impressive.”

Certainly, no one could have predicted this start from Sanchez, regardless of how hyped he had been over the years.

One American League scout who watched him each of the last two seasons at Triple-A Scranton/Wilkes-Barre pointed to the fractured right thumb Sanchez suffered in May.

“No one would have predicted this about anyone, but he showed some of this earlier in the year [with Scranton/Wilkes-Barre],’’ the scout said. “Then he got called up for that one game and got sent back down. Then he hurt his thumb, so that might have gotten to him.”

Asked what he has liked most about the young catcher, Teixeira couldn’t keep himself to one aspect.

“I think the home runs, number one, but his arm,’’ Teixeira said. “I don’t know if I’ve seen an arm on a catcher like that in a while.”

Then he came up with one — and did little to quiet the expectations that have quickly been placed on Sanchez.

“Pudge Rodriguez, when I was a rookie in my first spring training, he was still in Texas, throwing BBs,” Teixeira said. “That arm is right up there with Pudge’s when he was in his prime. … You’d better make sure you’re safe, because if he has any chance to get you, he’s gonna get you.’’

All that has helped the Yankees look ahead, despite their insistence the focus remains on 2016.

But with two straight losses heading into Tuesday’s game against Seattle at Safeco Field and a bullpen beginning to suffer from the loss of Andrew Miller and Aroldis Chapman, it’s only natural to think about seasons to come.

“You just marvel at what he’s doing right now and enjoy it,” Teixeira said. “The hope is he stays healthy and has a great career. But his first few weeks are proving to be pretty exciting.”

Even if they haven’t resulted in a lot of victories for the Yankees.

For all Sanchez’s exploits, the Yankees were just 8-8 in his 16 games since he had been recalled from the minors.