The most visible player the Rays received came in return for Moore in the form of Matt Duffy from the Giants.
"All of these guys are going to contending teams," Rays manager Kevin Cash said. "We wish we were in that position. We wish we didn't have to do that. But we have to do what's right with the organization today moving forward."
In addition to Duffy, the Rays received prospects, shortstop Lucius Fox and right-hander Michael Santos from the Giants.
Pearce went to the Orioles in exchange for Minor League catcher Jonah Heim. And Guyer will call Cleveland home after the Rays sent the outfielder to the Indians for prospects, outfielder Nathan Lukes and right-hander Jhonleider Salinas.
Duffy, who is recovering from a left Achilles strain and is on a rehab assignment, is batting .253/.313/.358 with 11 doubles, two triples, four home runs and 21 RBIs in 70 games.
"He's a guy who came up as a shortstop," Cash said. "He's played everywhere in the infield. We're really excited to have him."
Cash told reporters he'd just finished a phone conversation with Duffy.
"He's excited to get here," Cash said. "I don't think we're totally ready to say, 'He's going to do this for us.' But we're excited. We have to talk to some of our guys internally and figure out what's best for us going forward."
Duffy has only played third base for the Giants this season, though in the past, he's played shortstop, second base and one game at first base.
"Obviously, we have a third baseman in Evan Longoria, he's as good as anybody in the game, so [Duffy] will not be playing third," Cash said. "But we do look at him playing some short. He's versatile that he can play second. And obviously, spell Longo at third."
Cash said it was his understanding that Duffy is nearly finished with his rehab.
"I think he's very close," Cash said. "We're going to fly him in here tomorrow. Let [head athletic trainer] Ron Porterfield and our medical staff look at him. And then we'll decide whether he goes to [Class A] Port Charlotte or [Triple-A] Durham."
Cash added that the Rays do not envision Duffy playing first.
Moore has one of the most affordable contracts in the Majors and is under control via club options through the next three seasons. The 27-year-old lefty is 7-7 with a 4.08 ERA in 21 starts this season after experiencing injuries the previous two years.
"I actually was pretty surprised," Moore said. "I think even going into today, just kind of leaving my phone away from myself. Just the temptations and the things like that weren't around me. Just going about a normal day, and when 4 o'clock came around, I just thought things were staying the same. But there's definitely a lot of different feelings floating around."
Moore allowed that he'd "been around just long enough to understand that the business side of things tends to take over, especially around this day each year."
"I'm wishing them the best moving forward," Moore said.
Cash called it a "balance" that the Rays "have to constantly factor in our situation here."
"It's a luxury that we have players that teams want," Cash said. "Sometimes we have to make difficult decisions. And I can tell you, all three of these were difficult for everybody involved."
Moore said he'd be available to pitch on Tuesday for San Francisco, if needed. Moore said he's also spoken on the phone with Giants manager Bruce Bochy and general manager, Bobby Evans, adding that he was excited.
Fox, a shortstop who is ranked third on MLBPipeline.com's list of the Top 30 Giants prospects, while Santos, a right-hander, is ranked 24th.
Hiem is considered by many to be the best defensive catcher in the Orioles' organization and was their No. 13 prospect.
Salinas, 20, was pitching for the Rookie-level Arizona League Indians. Lukes, 22, was playing at Class A Lake County.
Cash was asked if the trades would impact his team.
"There's no way that it doesn't impact because these were three guys who played key roles," Cash said. "We're going to have to come together a little bit more. We're going to get some opportunities to see some different players play out there in those positions. In the long run be better for it. But right now, it's a little bit of a shell shock.
" ... We're missing our starting pitcher for tomorrow. We're missing who was going to hit fourth for us tonight. And probably who was going to hit second for us tonight. It is a little bit of a shock, you just have to adjust. This entire industry and game is about adjustments."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.