The biggest puzzle piece that the Yankees must fit into their everyday equation is en route back to the big-league club. Now, the real fun begins.

Giancarlo Stanton’s return from painful tendinitis in both elbows has been kept nicely under wraps during the Yankees’ surprisingly potent start to the season. Sometimes, when Aaron Boone’s spoken on it, he’s indicated that Stanton might not need a rehab assignment at all, creating questions about exactly how intensely he’s been working out behind closed doors. No matter the circumstances, Boone has worked hard not to betray too much optimism, while still raising his eyebrows and hinting at a potential high-impact arrival.

After writing him off (prematurely, but anxiously) in spring training when he first reported to camp with these cascading maladies, Yankees fans were thrilled to see Stanton appear on the field for a batting practice session on May 7. He didn’t look quite himself, scooping pitches rather than ambushing them, but in March, “never seeing Stanton in action again” felt like a reasonable fear. It was reassuring to both know the attempt was happening, and to detect a refreshing level of confidence that led to turning it into a public spectacle.

Now, a few days after Andy Martino floated an optimistic timeline, Stanton is officially on the clock: his rehab assignment starts Tuesday night in Somerset. From this date forward, the Yankees have a maximum of 20 days to get Stanton ready for an MLB return.

Yankees announce Giancarlo Stanton will begin rehab assignment with Somerset on Tuesday, June 10

The Yankees’ 39-25 start has been fueled by a largely better-than-expected offense, with Ben Rice and Trent Grisham filling what appeared to be gaping holes. But Grisham has slowed down over his past month (.215 with a .393 SLG in his past 30 games), and Rice has been one of the unluckiest hitters in baseball.

Besides, both Rice and Grisham are lefties, which is valuable at Yankee Stadium and has been deprioritized by the Yankees in recent years (for whatever reason). Suddenly, though, Stanton’s righty pop represents a rarity; the Yankees could really use some balance in the opposite direction.

When Stanton returns — which now, hopefully, is a “when” not “if” — Rice will remain. Stanton won’t play every day. Rice will spell Goldschmidt and he’ll rotate into the DH slot. What the Yankees will lack in lineup flexibility they’ll make up for in light-tower power and frequent refreshers and breathers for the big man.

Finally, after feeling like his Yankees career might end with a whimper, it all begins anew today.