Belfiore was designated for assignment on Sunday as the Orioles cleared space for reliever Evan Meek and outfielder Delmon Young on their 40-man roster. They also placed reliever Edgmer Escalona on the 60-day disabled list.
Belfiore, acquired from the Diamondbacks on May 12, 2012 as the player to be named in the Josh Bell trade, allowed one run and five hits in two innings with the Orioles last season and went 2-1 with a 3.18 ERA in 37 games at Triple-A Norfolk.
Norfolk opens its season tonight, but veteran pitchers Johan Santana and Luis Ayala are on the minor league disabled list and remain in Sarasota.
Also, Major League Baseball announced that Orioles third baseman Manny Machado has the 10th-most popular jersey since the conclusion of the 2013 World Series, based on sales on MLB.com/Shop of Majestic jerseys.
Here's the Top 20:
1. David Ortiz, Boston Red Sox
2. Dustin Pedroia, Boston Red Sox
3. Derek Jeter, New York Yankees
4. Yadier Molina, St. Louis Cardinals
5. Clayton Kershaw, Los Angeles Dodgers
6. Andrew McCutchen, Pittsburgh Pirates
7. Buster Posey, San Francisco Giants
8. David Wright, New York Mets
9. Robinson Cano, Yankees/Mariners
10. Manny Machado, Baltimore Orioles
11. Yasiel Puig, Los Angeles Dodgers
12. Bryce Harper, Washington Nationals
13. Miguel Cabrera, Detroit Tigers
14. Mike Trout, Los Angeles Angels of Anaheim
15. Matt Harvey, New York Mets
16. Prince Fielder, Tigers/Rangers
17. Adam Wainwright, St. Louis Cardinals
18. Koji Uehara, Boston Red Sox
19. Yu Darvish, Texas Rangers
20. Jacoby Ellsbury, Red Sox/Yankees
And finally, fans can begin voting today to select the player they want to be immortalized in a bobblehead giveaway that's scheduled to be distributed during Fan Appreciation Weekend on Sunday, Sept. 21 to the first 25,000 fans age 15 and over.
The choices are pitchers Tommy Hunter, Ubaldo Jimenez, Darren O'Day and Chris Tillman.
Fans can vote three ways throughout the promotion. The first is through unlimited mobile voting by texting 1 for Hunter, 2 for Jimenez, 3 for O'Day, and 4 for Tillman to 31826. Texting is available on all mobile carriers and is subject to standard text message rates.
Each time fans text their vote using their mobile phone they will automatically be entered into a sweepstakes for a chance to win a VIP experience that includes four lower box tickets to attend the September 21 game and an autographed bobblehead of the 2014 Fans' Choice Bobblehead player, plus an on-field experience prior to the game.
Fans can also vote on the Orioles website at www.orioles.com/bobblehead. Voting will conclude on Monday, May 12 at noon.
The past two seasons, fans have voted shortstop J.J. Hardy and first baseman Chris Davis as AT&T Fans' Choice Bobbleheads.