After days of seemingly trending away from Castillo as an every-day player, manager John Farrell said Tuesday that left field will be "a little bit of a platoon-matchup type of situation," with lefty-hitting utility man Brock Holt getting the majority of the action.
"At this point, unless he's on the infield somewhere, yeah," Farrell said of using Holt in left field. "I think he's earned a lot of it. This is a guy, his value continues to grow."
Holt played seven positions last season, batting .280 with a .727 OPS and serving as the Red Sox's lone representative in the All-Star Game.
Castillo, meanwhile, appears to be moving in the opposite direction. After signing a seven-year, $72.5 million deal in August 2014, the largest contract ever for a Cuban defector, he has batted .262 with a .681 OPS in 309 at-bats in a big league career interrupted by injuries.
With a chance to win the job in spring training, the righty-hitting Castillo was 10-for-44 (.227) with a .542 OPS in 16 games entering play Tuesday against the Minnesota Twins.
Veteran outfielder Chris Young is expected to play left field against left-handed pitching, raising questions about Castillo's role. Farrell said Castillo will be used as a fill-in in both left field and center, making him essentially a fifth outfielder. Defensive whiz Jackie Bradley Jr. is expected to get most of the playing time in center field.
"The area that he continues to work at is just the offensive side of the game. That's got to gain some consistency," Farrell said of Castillo. "And that's part of his own knowledge of who he is and what his swing is capable of and how that matches up with certain types of pitches."