The Red Sox have announced the starters for Tuesday and Wednesday of this week, against the Kansas City Royals. Justin Masterson will be brought up on Tuesday, swapped with Chris Smith (who came up today). Then Masterson will return to the minors after the game, and Bartolo Colon will come up to the big league club and will pitch on Wednesday.
That leaves the rotation as follows for this week:
Sunday: Josh Beckett vs. Carlos Villanueva
Monday: Jon Lester vs. Luke Hochevar
Tuesday: Justin Masterson vs. Gil Meche
Wednesday: Bartolo Colon vs. Brett Tomko
Thursday: Daisuke Matsuzaka vs. Brian Bannister
Since Masterson's April 24 debut against the Angels, the starter has struggled with Portland. Over his last four starts, he has given up 16 earned runs in just 19 1/3 innings. He has taken the loss in three of those four games.