OAKLAND, Calif., - At a time when they're carrying more players than ever, the Twins found themselves oddly shorthanded on Friday.

Miguel Sano, feeling occasional "jolts" of pain behind his left knee, returned to Minneapolis after the Twins' series in Detroit, and won't face the A's this weekend. Eddie Rosario and Mitch Garver are already back in the Twin Cities, their seasons ended by injury. Addison Reed drove from Detroit to Canton, Ohio, to be with his wife, who is due to deliver the couple's second child. And Logan Forsythe woke up Friday morning with a left knee that "was not functioning correctly," as manager Paul Molitor put it.

"We're a little bit banged up," Molitor said.

Sano's absence is the most concerning, because the pain in his left leg, a problem since he slid hard into second base on Aug. 4, "has persisted," Molitor said. "He's continuing to complain about discomfort behind his left knee, on that right side. It seems more like he was getting a nerve-jolt sensation at times, so we sent him back for more testing to find the source of that." With only one week left in the season, and considering his brief and unsuccessful return to action in the final weekend of 2017, it's possible that Sano, who batted .199 with 13 homers and 115 strikeouts in 71 games, won't play again this year. The Twins hope that's not the case with Forsythe, the second baseman who had missed only two games since being acquired from the Dodgers on July 31. "He has some inflammation in [his left knee], so we backed him off today," Molitor said. How did the injury occur? "He doesn't really know how or why," Molitor said. "The hills of San Francisco are our best guess." Garver, the rookie catcher battling a concussion suffered when he was hit on the mask by a foul ball on Sept. 12, is feeling better, Molitor said, but won't return this year. And Rosario, who aggravated his strained right quad in Detroit, underwent a magnetic resonance imaging test which found "no surprises," Molitor said. "It's fairly unlikely we'll see him [this year]."