While Sierra, 26, has hit .320 this spring entering Friday's action, he has no homers and just one RBI. Orlando, 29, is hitting .367 with one homer and seven RBIs.
Manager Ned Yost said of Orlando, "He's done everything well. He plays solid defense in all three outfielder spots. He's a true center fielder. He's swinging the bat really well. He has made great strides the last couple of years. He's athletic and can run. He fits our profile."
Jeffrey Flanagan is a reporter for MLB.com. Follow him on Twitter at @FlannyMLB. This story was not subject to the approval of Major League Baseball or its clubs.