Around the horn: Showalter said left-hander Brian Duensing (elbow) will be added to the roster on Monday, and is joining the Orioles at Camden Yards Sunday before their flight to Tampa. That will require the creation of a 40-man roster spot, as will another possible move, Showalter said. He mentioned reliever Pedro Beato and infielder Paul Janish as possible non-roster additions. … Right-hander Chris Tillman (shoulder bursitis) and reliever Darren O'Day (rotator cuff strain) had bullpen and half-mound sessions Sunday, respectively, though Showalter did not have an update. ... The Orioles will begin a camp for possible late-season additions to stay active at on Friday in Sarasota. Showalter listed catchers Audry Perez and Chance Sisco, left-handers Kyle Lobstein and T.J. McFarland, right-hander Parker Bridwell, first baseman Trey Mancini, and outfielders Dariel Alvarez, Chris Dickerson, Julio Borbon, and Christian Walker as possibilities to go there. Some of those players' statuses depend on whether they're used as countermoves for their pending roster additions, he said.