Jacoby Ellsbury's recovery from a rib contusion isn't coming along as quickly as hoped, so the Red Sox have placed the left fielder on the 15-day DL.

Outfielder Darnell McDonald has been called up from Triple-A Pawtucket to replace Ellsbury on the active roster. McDonald will be on the bench for Tuesday's game against the Texas Rangers.

Ellsbury was injured April 11 when he slid for a pop-up and was kneed by third baseman Adrian Beltre, who was also chasing the ball. Ellsbury has yet to play since. He holds a .333 batting average in 30 at-bats over six games so far this season.

Ellsbury's DL assignment is retroactive to April 12, the furthest back a player can be retroactively placed on the disabled list. He will be eligible to return during the final series of April at Toronto, likely on the 27th.

McDonald has spent parts of three seasons in the bigs with the Baltimore Orioles, Minnesota Twins and Cincinnati Reds since 2004. In 105 at-bats for the Reds in 2009, he hit .267 with two home runs.

The 31-year-old was tearing the cover off the ball down in Pawtucket — to the tune of a 1.055 OPS — and can play all three outfield positions. With his arrival from Pawtucket, the Red Sox' 40-man roster is now full.

Josh Reddick joined the Red Sox earlier Tuesday after Mike Cameron was also placed on the disabled list. Reddick is starting in center field and batting ninth against the Rangers.