Manager Kevin Cash told reporters in his office that Rivera had been released. Minutes later in the clubhouse, Loney revealed that he will not be on the team, meaning the Rays will trade or release him in the coming days.
The Rays have not confirmed Loney's status with the club.
The Rays also announced that right-hander David Carpenter and knuckleball hopeful Dan Johnson had been released. Third baseman Richie Shaffer and right-hander Matt Andriese were optioned to Triple-A Durham.
Tuesday's moves left 30 players in camp. The team must reduce that number to 25 by Sunday at noon ET.
Rumors about Loney's fortunes have circulated the length of the offseason and continued through Spring Training.
"They told me [I] don't have to come back," Loney said. "There's not a trade right now."
Loney allowed that he will be in limbo the next few days while waiting to see if he is traded or released.
"I think it will work out for the best for me," Loney said. "The team was great. Obviously, I wish them the best. The guys were great. Loved my time here. Loved the organization, how they gave me a chance after 2012. But at the end of the day, you want to play in the big leagues and you want to win, obviously. So we'll see how that goes.
"I would have liked to win with these guys. But at the end of the day, it is a business. So those aren't my decisions. I had nothing to do with that."
Loney's departure brought clarity to the first-base situation, which appears to be a platoon setup between right-handed-hitting Steve Pearce and left-handed Logan Morrison.
The Rays signed Loney, as a free agent, to a one-year, $2 million deal on Dec. 6, 2012. They re-signed him on Jan. 3, 2014 to a three-year, $21 million deal. He will make $9.667 million in 2016.
Loney hit .280 with four home runs and 23 RBIs in an injury-plagued 2015 campaign. The slick-fielding first baseman hit .291 with 26 home runs and 176 RBIs in 417 games with the Rays.
Rivera's release means the Rays will begin the season with Curt Casali and Hank Conger splitting time behind the plate. Who will catch on a daily basis will primarily be decided based on matchups.
"They both do things really well," Cash said. "They get there a different way. Curt, overall, has done a nice job of continuing to work with the pitchers. Offensively he's swung the bat pretty well this spring. Hank is a guy that we like. The pitchers love throwing to Hank. They've all raved about the way he receives the ball. He's gotten to know our pitchers really well. He has actually swung the bat really well, too."
Rivera came to the Rays from the Padres as part of a three-team trade on Dec. 14, 2014, that also involved the Nationals. The Rays sent outfielder Wil Myers and catcher Ryan Hanigan to the Padres along with Minor Leaguers Jose Castillo and Gerardo Reyes. They also received Minor Leaguer Jake Bauers and Burch Smith from the Padres and outfielder Steven Souza from the Nationals.
Rivera hit just .178 with five home runs and 26 RBIs last season and lost his starting job. Despite struggling offensively, he continued to play solid defense. During the offseason, he worked on hitting the ball the other way and arrived to camp optimistic that he had changed his fortunes. Rivera is owed $1.7 million by the Rays in 2016.
"Obviously a little bit of a difficult day today," Cash said. "You've got guys who were competing for jobs. Rene was with us all year. And to his credit, he came in and did some good things during Spring Training.
"We just didn't see it as the best fit on the club going forward. He handled it like a pro. And I think we're all confident we'll see Rene down the road in the big leagues, because he does some things that can really help a pitching staff and a team out."