Hassan, 24, has yet to see action with the Red Sox, but was added to the 40-man roster in November to protect him from the Rule 5 draft. Hassan has consistently shown the ability to get on base, holding a career .391 OBP in four seasons in Boston's farm system, but so far that's the only dimension to his game. He lacks significant power, is an unimpressive defender, and has only 16 stolen bases to his name.
Still, Hassan is depth at a position that may need it. With Ryan Kalish out for the foreseeable future, Hassan is the only available outfielder on the 40-man after Jacoby Ellsbury, Shane Victorino, Jonny Gomes, and Daniel Nava. With all four of those players expected to have a significant role for the team, the Sox could find themselves stretched very thin with an injury to any of them.
If Hassan is not looking ready to play come April and the Sox find themselves in need, they will likely have to shift Hassan to the 60-day disabled list in order to add another outfielder to the roster. The question will be if they then play it safe, adding the likes of Ryan Sweeney (assuming he's still there) or Juan Carlos Linares to the roster, risking whoever eventually has to be removed, or take the risk of calling Bryce Brentz up (perhaps early) in order to have the best possible player on the team.
Either way it's a sobering reminder of how thin the Sox are in the outfield at the moment.