Lin, 24, appeared in nine games for the Red Sox last year in his Major League debut, going 3-for-12 with a run scored and five strikeouts. He appeared in one game in April in place of the injured Jacoby Ellsbury before rejoining the team in May to provide outfield depth after injuries to Ryan Sweeney and Cody Ross.
The right-handed-hitting Lin was signed by the Red Sox as an international free agent in 2007 and is a career .256 hitter, with 22 homers, 216 RBIs and 145 stolen bases in 2,379 Minor League at-bats. He hit .247 with two homers, 30 RBIs and 15 steals last season at Triple-A Pawtucket.
In 2008, Lin was considered one of Boston's top prospects, and he homered in that year's Futures Game at Yankee Stadium. He went 2-for-2 and was named the game's Most Valuable Player.
Del Rosario, 27, made 19 relief appearances this season, going 0-0 with a 9.00 ERA. He spent the majority of his campaign at Triple-A Oklahoma City, where he went 4-1 with a 5.01 ERA in 36 appearances. He was acquired by Houston from Cincinnati in exchange for cash considerations on Sept. 16, 2010.