Less than an hour after that deadline passed, he announced in a conference call that Trembley would be sticking around.
"I think it's pretty self-evident that we won't be making any managerial change in-season," he said. "I think in terms of beyond this season, I'll sit down with Dave and we'll talk a little bit about the future when they get off the road.
"Like I've said many times before -- and I think most people agree -- that certainly Dave has done a very nice job with the team."
Trembley, who had managed 20 years in the Minor Leagues before getting a full-time job in the Majors, seemed like a long shot to keep the job when MacPhail first arrived. The Orioles made a run at hiring former Florida manager Joe Girardi in a move MacPhail dubbed a "pre-emptive strike," but when that didn't work, they settled in for the long haul.
Baltimore has gone 20-15 since Trembley took over the reins, and MacPhail has increasingly seen the difficulty of hiring a full-time manager with a dwindling amount of season left to play. Over time, he came to appreciate that nobody will be a better fit right now and that the players have given their tacit seal of approval by playing well under their new field boss.
"The terms that I have always thought were important -- and said really from my first press conference -- was the preparation level, the energy, the effort and the enthusiasm level that the players were displaying," MacPhail said Tuesday. "Certainly, I think you have to be pleased with all those things to this point."
Trembley, one of just seven all-time big-league managers who never played professionally, has said all along that he was thankful for the opportunity and fine with the open-ended nature of the job. He said he rarely thought about his long-term future, preferring instead to focus on preparing his team for every individual game and every situation they might face.
"I wasn't given any promises on how long it was going to be. I didn't ask and they didn't tell me," Trembley said. "Mr. MacPhail came out and said that he'd make a decision after the trading deadline and he did. I've gotten more than I could have asked for. That's how we try to be with the players. We try to be fair. When people treat you that way, that's really all you can ask for."
The Orioles may or may not resume their managerial search in the offseason, but true to form, Trembley's not allowing himself to think of what comes next. In his mind, MacPhail will tell him whenever he's good and ready.
"He told me that when we come back off the road, he would sit down with me and talk about some personnel issues and tell me the direction that he wants to go," he said. "He didn't tell me anything about next year. He said that we'll sit down and talk about the rest of the season and we'll touch base on where I think philosophically that the club ought to go next year."
Bumps and bruises: The Orioles aren't any closer on a decision on when to re-activate Melvin Mora, who missed most of July with a sprained left foot. The veteran is set to take batting practice and infield drills over the next few days and to try running the bases Wednesday before Baltimore decides whether to send him on a rehab stint.
"Tomorrow, it's his last stage of the rehab," Trembley said. "He's got to run the bases, and after that, we'll make a decision. ... I would think after he runs the bases tomorrow, that will all take care of itself."
Baltimore has sketched out a plan for utilityman Freddie Bynum, who's been out a few weeks with a strained left hamstring. First, he'll spend a couple days working out with Baltimore affiliates and then he'll run through a five-game trial run.
"He's going to play Thursday through Monday," said Trembley. "The plan is one game at short, one game at second, one game at center, one game at left, and the last game we're going to let him decide where he wants to play. The first game, I'd like him to play six innings and get three at-bats, and then the last few, he can decide how long he wants to play."
Swap meet: The Orioles were quiet at the non-waiver trading deadline, and Trembley said he was glad to see his entire team remaining intact.
"I think it takes a lot of pressure off of these guys," he said. "Obviously, it's a different time of year with the trade deadline and all that, but it's nice to know that you're going to be here. I'm glad we're all going to be here together."
Quotable: "I'm just kind of getting started. There's still room for improvement. There's still things that we'd like to do. We're going to do our best to continue doing things the right way." -- Trembley on the near future
Coming up: The Orioles and Red Sox will continue their series Wednesday at 7:05 p.m. ET. Boston's scheduled starter, Kason Gabbard, was traded Tuesday and will cause some internal shuffling. Steve Trachsel will start for Baltimore.
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.