Currently the O's are locked in with Adam Jones in center and Nick Markakis in right. Lough will compete for playing time with Nolan Reimold, who has played in just 56 games over the past two seasons due to multiple neck surgeries.
Reimold hits right-handed and Lough hits left-handed, so it's likely a platoon situation could evolve in left unless one of the two earns the everyday job in Spring Training. It's also not out of the question that the team could make a move to add another outfielder.
Lough, 27, hit .286/.311/.413 in 96 games for Kansas City last season while playing all three outfield positions. He finished eighth in the American League Rookie of the Year Award balloting.
Lough ranked ninth among outfielders who played at least 500 innings with a plus-14.5 ultimate zone rating (UZR). He was originally selected by the Royals in the 11th round of the 2007 First-Year Player Draft.
Valencia, 29, hit .304/.335/.553 in 170 plate appearances for the Orioles in 2013.
The O's outfield depth took a hit when Nate McLouth, who played all three outfield positions in '13, signed a two-year, $10.75 million deal with the Nationals last week.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.