Casas went 2-for-3 with two walks, two home runs and four RBI for Double-A Portland on Saturday.
Casas had been in an extended power drought since the middle of July, hitting just one homer over 20 games (66 at-bats), but the Red Sox's No. 1 prospect busted out this weekend. Including the three home runs he belted during Friday's doubleheader, Casas has five in the last two days.