Swihart severely sprained his left ankle on June 4, when his foot got caught in the base of the side wall in the left-field corner.
It's doubtful Swihart will be able to catch for the rest of the season, but the Red Sox feel he can recover enough to return to left field, where he had a smooth acclimation to after learning the position earlier in the season.
"He's been taking BP from both sides of the plate, but it's more the ground-based explosiveness that's being factored in now," said Farrell.
• Clay Buchholz, who was removed from the rotation for the second time this season after the Red Sox acquired Drew Pomeranz, hasn't pitched since July 2. Given Buchholz's lack of experience as a reliever, Farrell isn't looking to put him in any high-leverage situations.
"I don't want to say it's purgatory, but as far as baseball goes, he's in a difficult spot because of a four-day layoff over the break, and we've played very good winning baseball," said Farrell. "We've gotten starts deeper into ballgames where the bullpen has been rested and that's where the decisions have been made."
Joe Kelly, who is pitching well in relief for Triple-A Pawtucket, should be a much better fit for Boston's bullpen when he is recalled. The challenge at the moment is finding a roster spot.
• Red Sox reliever Koji Uehara told the Japanese media he expects to miss about a month with his right pectoral strain.
"Personally, I still don't have an idea of when or how long this injury will keep him out," Farrell said. "We talked about the uniqueness of the pec being injured. From a pitcher's standpoint, it's typically the shoulder that goes before the pec. In this case, on one pitch, that's where he felt it. I don't have any further updates from last night to today."
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.