Welcome back to another episode of the Chicago White Sox’ rebuild — and another episode of the White Sox losing streak.

Though team employees are loathe to use that word to describe Chris Getz’s long-term reconstruction project, that’s what it is. And I can tell you that because I’m hearing the same kinds of things — and seeing the same kinds of things — I saw the last time this happened on the South Side.

Tuesday night, I had to look around and remind myself I wasn’t listening to Rick Renteria talk about Lucas Giolito, because “learning experience” was being bandied about like the homers were flying out of Wrigley Field.

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Not unjustifiably, of course. The White Sox are building for the future, and this whole season is about learning what they have and where they need to go from here. Putting guys like Jordan Leasure on the Opening Day roster, and calling up Double-A players like Bryan Ramos and Duke Ellis in the middle of the season, is doing just that.

Those guys need to learn what it’s like to be major leaguers if they’re going to help the next contending White Sox team.

In the interim, though, it’s going to mean losses. And a lot of them. Like a dozen of them in a row.

That’s what the White Sox’ miserable losing streak stretched to Tuesday on the North Side, the bullpen coughing up a 5-0 lead and then the 6-5 lead earned by Luis Robert Jr. homering in a big spot in his first game back from the injured list.

Getz’s front office obviously already knows that Robert is good, and that’s why the first-year general manager called Robert a player to build around when he talked about how unlikely he would be to deal the superstar center fielder during the Winter Meetings. But they know far less about what sort of major leaguers Leasure and Ellis will be.

Leasure was the one to give up the Robert-won lead, walking Cody Bellinger on four pitches in the eighth inning ahead of an infield single off Christopher Morel’s bat and the Ian Happ two-run double that decided the game.

The rookie reliever has been mostly excellent during his first taste of the big leagues, starting his career with seven scoreless outings and bringing a 2.52 ERA into Tuesday. But he’s put the White Sox in a lot of sticky situations of late; in his last 10 appearances, he’s walked nine batters.

“The walk to (Bellinger), I was pretty frustrated with that,” he said after the game. “There’s been some up and downs lately. There’s been a few more downs than ups, obviously. But still just learning from each outing, even the good ones. Being kind of thrown into some high-leverage situations early on, it’s all just a learning experience.

“Sometimes it works out, sometimes it doesn’t. That’s baseball. Just trying to learn from each one.”

See? Learning.

If Leasure was “thrown into” high-leverage situations, then what do we call Ellis getting chucked into a game-on-the-line situation as a ninth-inning pinch-runner after coming up from Double-A earlier in the day?

With the White Sox down a run, Ellis subbed in and instantly stole second base, exactly what the speedster is here to do. His 34 steals ranked second in all the minor leagues, and he used that ability to put the potential tying run in scoring position. But he didn’t put that same immediate pressure on Hector Neris when efforting a steal of third, and he paid for it, the Cubs’ closer catching him dancing for a critical pickoff, the second out of the soon-to-be-over ninth inning.

“That’s what he’s here for,” Pedro Grifol said. “He’s being aggressive. He got picked off. He’s here to help us win, and he’s going to learn from this. … He’s an exciting player, an exciting baserunner. He was put there to do exactly what he did, and he got picked off. It’s not a big deal. That’s not what won us or lost us the game.

“He’s a student of the game. He’s going to learn from this. And I want him to continue to be aggressive. I don’t want him to shy away from anything. I want him to get after it like he did today.”

Learning abounds for these rebuilding White Sox.

We’ll see, of course, if these guys learn the right lessons and turn themselves into fixtures of the future Getz is trying to build. Leasure could wind up a future closer. Ellis could prove a special kind of weapon as a stolen-base artist. Right now, it’s the finding-out stage.

Unfortunately for the White Sox fans living through it, it means a whole lot of losing, the other thing plenty reminiscent of the franchise’s last rebuilding cycle. The South Siders are baseball’s worst team, with only 15 wins to their name, meaning the number of consecutive losses is getting dangerously close to the season win total.

Tuesday marked another new way to fail, the bullpen coughing things up on a pair of sixth-inning homers after the offense built a somewhat shocking 5-0 lead against early-season Cy Young candidate Shota Imanaga. For once, baseball’s least-productive offense was not the culprit.

But even when that was the case, the result was the same as it was the previous 11 times.

The White Sox have lost 16 of their last 17 games, and all focus is on who could be exiting at the trade deadline. Might Robert be among those departing? Getz would surely have to get a jaw-dropper of a return package to deal away Robert, who showed once more Tuesday why, even as he’s rediscovering his footing after a lengthy stay on the injured list, he’s a unique force in the middle of the lineup. And the White Sox could keep him in the middle of their lineup for another three and a half seasons.

But Getz, of course, wouldn’t be doing his job if he didn’t do some research and listen to what other teams have to say, find out if there’s a way to speed up or bulk up his rebuilding project.

It’s all part of the learning.