As it stands now, the Red Sox outfield is made up of Mookie Betts, Jackie Bradley Jr., Rusney Castillo, Brock Holt, and Bryce Brentz. There is a clear need for a legitimate bench outfielder who could start in an emergency, which makes Boston's interest in free agent outfielder Chris Young somewhat predictable. According to Bob Nightengale, the Sox have already reached out to Young early in the offseason.
Young played in 140 games for the Yankees in 2015, but only picked up 356 plate appearances as he was doing a lot of platoon work: just 62 of those games were starts that Young completed, with the outfielder either lifted or inserted into the rest. He crushed lefties to the tune of .327/.397/.575 over 175 plate appearances, and has hit them well in his career, with a line of .262/.362/.474. He's not great in center anymore, but he can still handle the position and play in the corners as necessary, making him an ideal fit for a bench bat you actually want to play sometimes.
Given the questions surrounding both Bradley and Castillo and their ability to produce over a full season -- Bradley's because of consistency concerns and Castillo's having to do with his health -- someone like Young who can pick up 400 plate appearances in an emergency without hurting the lineup overly much makes sense. With Bradley left-handed, it also gives Young an obvious spot to pick up some playing time should Castillo both stay on the field and thrive.
Young signed a one-year deal for $2.5 million for the 2015 season. He's likely to get a raise after his strong summer, and maybe two years instead of one, but nothing that would make him an unattractive addition to an outfield in need of depth is expected. There are other options, of course, such as Rajai Davis -- a player Dave Dombrowski already acquired once while with the Tigers -- but Young would certainly fit the bill if the two sides come to terms.