NASHVILLE, Tenn. -- Of the nine players projected to be in the starting lineup for the Red Sox next season, the man who comes with the least amount of certainty is Rusney Castillo.
Fifteen months after Castillo signed with Boston on a seven-year, $72.5 million deal, there are still questions about how much he will hit and whether he is durable enough. Castillo also needs to cut down on his baserunning mistakes.
But Red Sox president of baseball operations Dave Dombrowski still feels that Castillo can succeed, and that's why Dombrowski isn't roaming the halls at the Winter Meetings in Nashville trying to find another starting left fielder.
"Well, I think he's durable enough to do it, but he still has to show it," said Dombrowski. "That's why we do have [Chris Young]. We have other guys that we can play out there. But he needs to show that. There are factors behind that, because he's in a position where he defected [from Cuba]. He didn't really have a complete year the year before. Last year, he had some injuries."
While with the Tigers, Dombrowski actually tried to sign Castillo when the player was an international free agent, only to lose out to his future employer.
"We liked him," Dombrowski said. "We put a nice bid on him. We were nowhere close to the Red Sox bid. So we liked him, but I don't know if we were second or third. And we projected him ourselves -- right or wrong -- as somebody who could play center field for us. We needed a center fielder at that time, so we thought, 'OK, it's a guy we can give this money to and we can eventually put him in center field.'"
Dombrowski then added, "But fortunately, the Red Sox won."
Will Castillo wind up being the player the Tigers and Red Sox originally projected?
"He works hard," said Dombrowski. "He's very conscientious. But I really can't answer that question, because I don't know. He's working hard this winter. He's worked hard down in Florida. He's going to go spend some time with [hitting coach] Chili Davis in the next couple of weeks. He's doing everything he can, and we're doing everything we can. He wants to be a good player, this is a really driven player, but only time will tell [what happens]."
Due to the overload the Red Sox had in the outfield at the start of 2015, Castillo began the season at Triple-A. His initial call to the big club on May 22 lasted exactly a month, as Castillo couldn't get his bat on track.
The Red Sox recalled him again for good on July 27, the same day Shane Victorino was traded to the Angels. For a 137-at-bat stretch through Sept. 13, Castillo hit .321 with four homers, 22 RBIs and an .838 OPS while playing solid defense.
Then came a severe dip, as Castillo hit .129 over his final 62 at-bats, with no homers and one RBI.
"To me, it looked like he ran out of gas," Dombrowski said. "When I first saw him, he was really playing well all around. I don't know him well enough, but just from watching him play, it looked like his bat slowed down a little bit. It didn't look like he was quite the same. It looked like he had just hit a wall, and it was understandable, if that's what he did."
In Boston's highly athletic outfield that also includes Jackie Bradley Jr. and Mookie Betts, the 28-year-old Castillo is going to play left field after getting acclimated in front of the Green Monster late last season. Just how much Castillo plays will depend on how he performs and how his body responds to the rigors of the long season.
But a flourishing Castillo is the best-case scenario.
"Now, I'm sure, again, another year in the States, a winter of conditioning which he's doing, [those things] will help," said Dombrowski. "And [manager] John [Farrell] knows him, and will give him some time off if he feels it's appropriate at various times, to kind of conserve that. But sure, the durability, he still has to answer that question."
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.