The 24-year-old O'Brien has been showcasing his raw power at Double-A Trenton, where he entered play on Tuesday with 15 home runs and 35 RBIs in 42 games, owning a .228 (37-for-162) batting average.
O'Brien has seen time at catcher, first base, right field and designated hitter this season, with the organization looking to find a place to keep his bat moving through the pipeline.
A second-round pick in the 2012 First-Year Player Draft, O'Brien batted .321 (36-for-112) with 10 homers and 19 RBIs in 30 games with Class A Advanced Tampa before being promoted in early May.
The 20-year-old Severino was 3-2 with a 2.79 ERA in 14 starts for Class A Charleston this season, hurling 67 2/3 innings with 62 hits, 24 runs (21 earned), 15 walks and 70 strikeouts.
A product of the Dominican Republic who signed with the Yankees organization in 2012, Severino is currently with Tampa, where he has made one start. He is ranked as the Yankees' No. 9 prospect by MLB.com.
The 16th annual SiriusXM All-Star Futures Game will take place at 5 p.m. ET on Sunday, July 13, at Target Field in Minneapolis, and it can be seen live on MLB.com and MLB Network, and followed live on MLB.com's Gameday. In addition, XM Radio will broadcast play-by-play coverage of the event live on MLB Network Radio XM 89 and Sirius channel 209. MLB.com will also provide complete coverage before, during and after the game.
Fans can stay updated by following @MLBFutures on Twitter and can send and receive tweets to and from the U.S. and World Team dugouts during the game by tagging tweets with the hashtags #USDugout and #WorldDugout.
Major League Baseball, in conjunction with the Major League Baseball Scouting Bureau, MLB.com, Baseball America and the 30 Major League clubs, selected the 25-man rosters for each club. Each Major League organization is represented, and players from all full-season Minor Leagues were eligible to participate.
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. Jamie Ross is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.