James Paxton has begun showing the Yankees everything they envisioned.

And now Justus Sheffield can show the Yankees what they’re missing.

The top Mariners prospect, the jewel of the offseason trade that swapped lefty starters, is getting the call-up to the big leagues, Seattle manager Scott Servais told reporters Tuesday.

Sheffield will be leaving Triple-A Tacoma to supplement a Yusei Kikuchi outing Friday; the Mariners are having the rookie from Japan — and many of the younger starters in their system — throw an abbreviated start once a month or so to preserve his innings and health.

Kikuchi likely will throw an inning as a de facto opener, and Sheffield will be making his fourth major league appearance immediately after. Last year, the Yankees recalled the 22-year-old in September but utilized him out of the bullpen with no rotation slots available.

Sheffield is Seattle’s top-ranked prospect, according to MLB.com, and the 40th best in baseball. A year after dominating Triple-A Scranton/Wilkes-Barre competition (2.56 ERA), Sheffield began his Pacific Coast League stint with a 3.93 ERA in 18 1/3 innings.

“Justus just carries himself so well, and I keep saying that,” Servais told reporters after Sheffield’s first spring training outing. “But there’s a confidence level that he kind of knows this is his time. He’s done what he needs to do at the minor league level. He still has things to work on, but he wants to make a good impression, and it was very good today.”