BALTIMORE -- Orioles reliever Darren O'Day will not accompany the team to Toronto this weekend, with the right-hander dealing with worsening numbness and tingling in the fingers of his pitching hand over the past week or two.
"We're just trying to get a grip, or our hands around, what's causing it," manager Buck Showalter said of the injury to O'Day's index and middle fingers, which hampers his grip. "Because they have done a lot of structural tests. They've done blood, nerve, trying to get an idea exactly of what's causing it.
"It's sore. Fingers are sore at certain times. And [it's] just kind of going back and forth. He had a couple days where it didn't bother him at all. And it came back again."
O'Day -- who could go see hand specialist Dr. Brian Schofield in Sarasota, Fla., for more tests -- last pitched on Saturday, throwing two innings, and he has just two appearances this month, forcing Showalter to maneuver the bullpen differently without the late-inning righty.
"I present it as something that opens up an opportunity for somebody else to present themself well," Showalter said of replacing O'Day, who is 5-3 with a team-best 2.23 ERA in 63 outings. "That's the way last year, and a lot of times this year, we found some orchids while searching for roses and having a rose missing, and Darren's been that.
"It's killing him, because he sees situations [he should be pitching in]. ... [Having expanded rosters] creates some different things. I challenge our guys to, [if] somebody falls, somebody's got to take his place in the artillery line."
Showalter said he wouldn't rule out having O'Day join the Orioles on their three-city road trip, perhaps as early as Toronto, although that depends on what the finger tests reveal. One of the most outgoing personalities in the Orioles' clubhouse, the sidearming O'Day signed a two-year extension this spring with an option for 2015 after going 7-1 with a 2.28 ERA in 69 games in 2012.
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.