"Close again," Showalter said. "I expect him by the end of the day to be better."
Showalter said Jones will receive treatment during the game.
"He's still a little stiff," Showalter said. "He's available. If I said, 'Adam, let's give it a shot,' he'd be the first guy out there."
Jones is batting .269 with 27 home runs and 82 RBIs this season.
• Right-hander Miguel Gonzalez is scheduled to start Tuesday against the Blue Jays at Camden Yards. Gonzalez, who last pitched Aug. 30, has been on the disabled list with right shoulder tendinitis. The O's starter for Thursday's finale vs. Toronto has yet to be determined. Wei-Yin Chen is slated to start Friday against the Yankees.
• O's closer Zach Britton, who has not pitched since Sept. 20 due to a left-side lat strain, told reporters he expects to be available on Saturday.
• First baseman Chris Davis was penciled in at designated hitter Saturday for the first time since Sept. 17. Showalter said the slugger recently hit two balls off his shin and has a "pretty good knot" there.
Aaron Leibowitz is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.