"We're taking a look at that," he said. "But I will say that we've never taken the approach that we need a long man. We want the best pitchers. So, if we have to make an adjustment roster-wise, we've got flexibility with pitchers who have [Minor League] options in our 'pen. We want the best group and not defaulting because somebody can go two or three innings."
If Boston did use a long man, it might benefit right-hander Brandon Workman, who has started 18 big league games over the past two seasons.
However, that last spot also could go to a second left-hander to complement Craig Breslow. Boston has southpaws Edwin Escobar, Tommy Layne and Robbie Ross Jr. on the 40-man roster, with Dana Eveland in camp as a non-roster invitee.
Farrell was highly complimentary of Layne, who pitched in 40 games for the Padres from 2012-13 before signing with the Red Sox. At the time, Farrell said Layne "jumped out" among the group of Minor League free agents because of his strong numbers and scouting reports. Layne then posted a 1.50 ERA over 37 appearances at Triple-A Pawtucket and a 0.95 mark over 30 games with Boston, with lefties going 7-for-44 (.159) against him. This spring he has allowed two baserunners and struck out six over four innings.
"He's got exceptional life to his stuff," Farrell said. "He creates an uncomfortable feel, particularly to a left-handed hitter, because of the ability to change arm slots. And he maintained what he did in Spring Training all throughout the year in Pawtucket, and he came up and carried on.
"He can pitch a whole inning. But given the group we have here, he has the ability to get, I think, very good left-handed hitters out. That's not to guarantee anything for Opening Day, but he's doing everything within his ability to impact that."
The situation is less certain for Ross and Escobar. The Sox want to get Ross back to being the effective reliever he was for the Rangers in 2012-13 after a rough transition to starting last year.
Farrell didn't know whether the 22-year-old Escobar, picked up from the Giants for Jake Peavy last July, will work as a starter or reliever at Pawtucket if he doesn't make the big league club.
"He's got a chance to be a good reliever," Farrell said. "We see the velocity playing up in those shorter stints, which kind of separates him out from the group. A left-hander who can throw in the mid-90s, they're pretty valuable."
Outfielder Rusney Castillo was scheduled to progress to live batting practice on Monday, and Farrell said he "projects to be game-ready by Wednesday," when the Red Sox host the Twins. Castillo, who strained his left oblique on March 3, hasn't played in a Grapefruit League game, and Farrell is not sure if he will be ready for Opening Day.