There are varying levels of “sellers” in baseball. The Orioles are in the process of seeking their level.

They must get approval from ownership before making any significant deals. In the meantime, they’d definitely be willing to move outfielders Seth Smith and Hyun Soo Kim and catcher Welington Castillo.

Those are the smaller pieces that don’t get as much media attention.

Executive vice president Dan Duquette will listen to offers for closer Zach Britton and setup men Brad Brach and Darren O’Day, but again, it’s complicated because they’re still not officially “available.”

Being swept yesterday by the Cubs and falling a season-worst seven games below .500 could change that status in a hurry.

Smith and Kim are eligible for free agency following the season. Smith continues to play right field against right-handers, though he’s moved down from the leadoff spot. Kim barely gets off the bench and he’ll become invisible with Trey Mancini moving back to left field.

Smith is owed the remainder of his $7 million option that the Orioles inherited from the Mariners in the Jan. 6 trade for pitcher Yovani Gallardo. Kim is owed the remainder of his $4.2 million.

Castillo is an interesting case. He holds a $7 million player option for 2018. It looks like an opt-out and quacks like an opt-out, but it’s regarded as a player option.

The Orioles want Chance Sisco behind the plate next season, and they’d take him later this summer. They’re fine with Caleb Joseph as a backup. They don’t need three catchers.

Here’s a question that’s based strictly on my curiosity and not inside information: If the Orioles designated Castillo for assignment, he cleared waivers, another team signed him and then released him after the season, what happens to the $7 million option? Are the Orioles on the hook for it? Or would the team that signed him and let him go assume responsibility?

Unless there’s a special stipulation in the contract, the Orioles apparently would be responsible. If anyone else was curious.

Anyway, Castillo is available if a team is looking for a veteran catcher.

The Orioles would get a bigger haul, of course, for one of their prime bullpen pieces. Just stating the obvious here. The question is how committed is the organization to a rebuild?

Don’t expect a complete overhaul like 2000, which set back the franchise for years. Melvin Mora wasn’t much of a return for Mike Bordick, B.J. Surhoff, Charles Johnson, Will Clark, Harold Baines and Mike Timlin.

Here’s the complete list:

* Bordick to the Mets for Mora, Mike Kinkade, Leslie Brea and Pat Gorman.

* Timlin to the Cardinals for Chris Richard and Mark Nussbeck.

* Johnson and Baines to the White Sox for Brook Fordyce, Miguel Felix, Juan Figueroa and Jason Lakman.

* Clark to the Cardinals for Jose Leon.

* Surhoff and Gabe Molina to the Braves for Luis Rivera, Trenidad Hubbard and Fernando Lunar.

The Orioles may be set in left field next season with Mancini, who isn’t going to supplant Chris Davis at first base. There are people in the organization who believe Austin Hays could be a starting outfielder in 2018, and Cedric Mullins also has plenty of supporters.

Drafted, developed, productive and inexpensive.

Meanwhile, Chris Tillman makes his first start tonight since June 30 against the Rays, his season interrupted by paternity leave and the break. He’s 1-5 with a 7.90 ERA and 2.143 WHIP in 11 starts, with 79 hits allowed in 49 innings. His only win came in his first start on May 7 against the White Sox.

Asked yesterday what he could expect from Tillman, manager Buck Showalter didn’t have a readily available response. How could he? To put it in Robert Andino’s terms, he’s no future teller.

“Not real sure,” Showalter said. “He’s had three work days counting the one he had at Bowie, so he’s certainly rested. But I’m hoping that he takes his new fatherhood to another level.

“I was kidding him the other day. I know some of you in here have had that moment. The first time you look in a crib and you go, ‘Oh gosh, I’m going to have to find something that I’m pretty good at that they’ll actually pay me for. There’s somebody down this hall that’s counting on me to be pretty good.’ I don’t know. I think Chris should be able to pay the bills.

“I’m anxious to watch him pitch and see if he’s going to have the last two-fifths of the season that he’s capable of. We thought it would benefit him with all the things that went on in his life to have two or three work days and be ready to go.”

Tillman is 3-2 with a 5.40 ERA and 1.475 WHIP in seven career starts against the Rangers over 40 innings. The current group is batting .349 (29-for-83) against him.

Adrian Beltre is 7-for-15 with two doubles and a home run. Elvis Andrus is 5-for-14 with a double and five walks.

The Orioles rotation has posted a 6.02 ERA in 91 games, worst in the American League and ahead of only the Reds (6.04).