Waiting on the roster move and Arrieta's start (updated twice)

BOSTON - The Orioles were off yesterday, but they stayed busy. Besides the private screening of the film "42," they made preparations for a roster move involving outfielder Chris Dickerson. As I wrote last night, outfielder Nolan Reimold's hamstring is fine and the move isn't expected to involve him. Dickerson isn't on the 40-man roster, but infielder Wilson Betemit can be transferred to the 60-day disabled list. Stay tuned. Dickerson just sent this tweet a few minutes ago: "Rise and shine!! Nice little birthday present, a trip to #Boston. A W would be even better. Time for takeoff." Did I expect Dickerson to be in the majors by April 10? Honestly, no, and it's nothing against him. I just assumed that the Orioles wouldn't have a need for him this early, and if they were going to make a roster move, it would involve a player such as Russ Canzler or Conor Jackson who handles multiple positions. Canzler hit his second home run last night and has driven in eight of Triple-A Norfolk's 16 runs. Yamaico Navarro had a walk-off single, but he's no longer on the taxi squad. He's staying with the Tides. The reasoning behind Dickerson's promotion should become more clear once we learn of the corresponding roster move. Update: There's lots of speculation about Steve Pearce being designated for assignment, but it doesn't make sense. Not after 10 at-bats. And why would the Orioles wait until Dickerson was written into Norfolk's lineup last night before making that decision? They could have summoned Dickerson much earlier in the day. I'm hearing the move doesn't involve Pearce, either. So again, stay tuned. Update II: The Red Sox have changed their rotation, starting right-hander Alfredo Aceves on Thursday instead of left-hander Felix Doubront. Manager Buck Showalter talked about holding Reimold out of tonight's lineup to make certain that the outfielder was available to face Doubront, who's now being pushed back. The Red Sox are deciding whether to place John Lackey on the disabled list. By moving back Doubront, they can buy a little more time. The Orioles will try to snap a three-game losing streak tonight and get back to .500, with Jake Arrieta taking the mound for the second time in 2013. Arrieta gave up five runs and seven hits over five innings in the Orioles' home opener against the Minnesota Twins. Tonight, he gets the Boston Red Sox, who are batting .313 against him in five career games, including four starts. Well, it's not the exact same team. The Red Sox have taken on a different look this year. However, they still have Jacoby Ellsbury, whose two hits in five career at-bats against Arrieta are home runs. Dustin Pedroia is 4-for-11 with a home run. David Ross is 2-for-2 with a home run and four RBIs. Shane Victorino is 3-for-3 with a double, home run and five RBIs. Small sample sizes. Arrieta is 0-3 with a 6.00 ERA against the Red Sox, with 31 hits, eight walks and 14 strikeouts in 24 innings. He's allowed six earned runs (seven total) and eight hits in 6 1/3 innings over two appearances (one start) at Fenway Park, with five walks and three strikeouts. Ryan Dempster is making his third career start against the Orioles. He's allowed only two runs and seven hits in 13 1/3 innings, with three walks and six strikeouts. He's held the Orioles to a .152 average. Small sample size.