Johnson, who started the game at DH, said he felt "a little pain" and some weakness after he fouled off a changeup during his only at-bat of the game in the second inning. He struck out swinging on the following pitch.
Manager Buck Showalter and Johnson said that team doctors plan to take an MRI.
"Get a picture, see what's going on in there and go from there," Johnson said.
Johnson has a history of right wrist injuries, most recently undergoing season-ending surgery in May 2010 when he was with the Yankees. He also missed all of the 2000 season and most of '08 due to right wrist issues.
Although he felt there were a few similarities between this injury and his previous issues, he said he was optimistic he could avoid the disabled list.
"Wait and see what the doc says," Johnson said. "It's not swollen. Some of the things in the past, it's not the same. See what happens."
Johnson had been healthy throughout 2012, posting a .207 batting average with four homers in 38 games.
Ryan Flaherty entered as a pinch-hitter for Johnson in the fourth and flied out to right.
Greg Luca is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.