Source: Mike Axisa, CBS Sports 
In all likelihood, the Red Sox view Beltran as a replacement for Jacoby Ellsbury, who is expected to leave the team for a nine-figure contract elsewhere. Boston could shift Shane Victorino to center field and the leadoff spot with Beltran taking over in right field and the second spot in the lineup.
He fits the Red Sox mold as a hitter who works deep counts, fouls off a bunch of pitches and hits for power. As an added bonus, he’s a switch-hitter and his generation’s best postseason hitter.
On the downside, Beltran figures to need more time at DH at this point of his career, and Boston is obviously set there with David Ortiz.