ST. PETERSBURG, Fla. -- Cuban outfielder Rusney Castillo will be with Double-A Portland Wednesday night in Binghamton, N.Y., when the Sea Dogs open their best-of-five Eastern League semifinal playoff series, Red Sox manager John Farrell said Monday.

Both Triple-A Pawtucket and Double-A Portland are scheduled to open best-of-five playoff series on Wednesday, the PawSox playing at home against Syracuse on Wednesday and Thursday, the Sea Dogs in Binghamton, N.Y. on the same days. The PawSox would then go to Syracuse for games Friday, and if necessary, Saturday and Sunday, while the Sea Dogs would return home to play Binghamton under the same format.

If either team wins its series, it would advance to the best-of-five league finals, which would open Sept. 9 for both the PawSox and Sea Dogs. If the Triple-A finals go the distance, they are scheduled to end on the 13th; the Double-A finals are scheduled to end on the 14th.

Castillo played five innings Monday for the Gulf Coast League Red Sox in the deciding game of their rookie league finals series against the GCL Yankees. Castillo grounded out in his first at-bat and drew a four-pitch walk with the bases loaded in his second plate appearance. He also hit into a force play and flied out to shallow right.

Farrell suggested that as long as Pawtucket or Portland was still playing, Castillo would remain in the minor leagues.

“Let’s get every available at-bat before those teams shut down before we entertain the thought [of Castillo taking] the next step with us,’’ Farrell said.

Adhering to that approach, Castillo could make his Red Sox debut on the next homestand, which opens Friday against Toronto, if the PawSox and Sea Dogs are both knocked out in the semifinals. If not, he could either join the Sox in Kansas City during their four-game visit there (Sept. 11-14) or in Pittsburgh, where they open a series against the Pirates on Sept. 16.