But there is a friendly rivalry brewing between the two, caused by bullpen-homer-gate.
In the fifth inning Saturday against the Toronto Blue Jays, first baseman Chris Davis launched a home run to left-center field. The ball was headed toward the visiting team's bullpen at Camden Yards when Hunter jumped up and caught it for a highlight that was listed among ESPN's top 10 plays of the day.
"I didn't want the other team to get the ball," Hunter said. "So I flew like an eagle, soared. Through the clouds to reach epic heights."
O'Day wasn't impressed with Hunter's glove work, though, finding it to be less than worthy of his own home-run snagging prowess.
"How about when I barehanded a home run ball, how about that?" O'Day said, calling up video of his two-handed catch of a bullpen home run against the Kansas City Royals earlier this year.
Hunter snapped back: "You cradled it like an old man, like a grandpa catching it for his grandson, against his body."
O'Day showed more evidence of his mastery: a video of him leaping at the second bullpen wall while outstretching former Orioles reliever Luis Ayala for the souvenir.
Yes, O'Day probably is the undisputed home-run-catching champion in club history.
But Hunter believes he is more than just a challenger now. He believes he is in possession of proof of his superiority. After catching Davis' home run, he had the Orioles slugger sign it.
Davis included the inscription: "Greatest HR catch. EVER."
"Ever," Hunter reiterated emphatically.
Hunter also explained why a reliever would be wearing a glove in the bullpen in the fifth inning, and it also speaks to the Hunter-O’Day rivalry. Hunter’s glove was behind him on the bullpen bench, but when Davis hit the ball, Hunter saw O’Day put on his glove. So Hunter did the same thing.
“The ball was hit, and I saw Darren, and I saw him turn around and reach for something. And I was like, ‘He is going to try and catch this,’ “ Hunter said. “So Darren gave me a little bump, I bumped him again, got him out of the way, cleared a spot and went over the bullpen [wall].”
Hunter landed on a catcher’s mask and stumbled, but he said he quickly recovered and “mean mugged” for the camera. He then got a high-five from, of all people, O’Day.
“I would put [Saturday] night right up there on my list, at least Top 3, [of] greatest moments ever,” Hunter said, “Just for the fact I got to knock Darren out of the way and prove my catch was better.”
With six starters, club has options
The Orioles plan to activate right-hander Miguel Gonzalez on Tuesday to start against the Tampa Bay Rays, which technically gives the club six starters, though manager Buck Showalter has maintained that he would prefer a five-man rotation.
One solution the manager mentioned was rotating starters into bullpen roles. That could prove particularly viable with right-hander Ubaldo Jimenez, who is slotted to pitch Friday against the New York Yankees, but has a 6.67 ERA in five career starts against the American League East foe.
"Anybody, not just Ubaldo, if there's a need. He's capable of [pitching out of the bullpen]," Showalter said.
Jimenez's start Friday would occur after two side sessions and on six days' rest. In those situations, the right-hander has a 3.38 ERA this year. His only career relief appearance was his major league debut in 2006.
To make room on the 25-man roster for Gonzalez, the Orioles will have to remove someone, likely a reliever. However, Showalter pointed out that several starters have minor league options remaining. That list would include Kevin Gausman, Gonzalez, Bud Norris and Wei-Yin Chen. They all have pitched well recently.
"At some point, you've got to fish or cut bait, because we have more than five [starters] right now," Showalter said.
Gausman understands his situation
Gausman, the rookie who has turned in two consecutive quality starts, is scheduled to take on the Rays on Wednesday. With Gonzalez coming back, though, Gausman knows his slot in the rotation is mostly contingent on how he pitches. And even that doesn't guarantee him a spot in the majors.
"I kind of look at it as, if I continue to pitch well, I stay here. If I don't, then they'll get someone else who can [do it] here," said Gausman, who is 2-1 with a 3.71 ERA in three starts with the Orioles this season. "It's kind of a tough situation, but this is my second year now, and I understand it now."
Gausman was called up for one game in May — a loss to the Detroit Tigers in which he allowed five earned runs in four innings before being sent back to Triple-A Norfolk. He was then recalled June 7.
In 2013, Gausman had three stints with the Orioles.
"My first time I got sent down, I took it kind of personal, but now I think that is just part of it, especially with this team," he said. "If you have options, they are going to use them."
Around the horn
Orioles catcher Matt Wieters, who has not played since May 10, will again see Dr. James Andrews about his strained right elbow Monday. The club should know Monday whether Wieters will require season-ending Tommy John surgery, which could occur as early as Tuesday. The team is expecting surgery will be needed, but won't give up hope until Andrews gives his recommendation. … Davis didn't play Sunday, more of a mental than a physical day off, though the club wants to make sure the oblique injury that hampered him last month doesn't return. He was available to pinch-hit and would have been used Sunday in the ninth if he had been in position to represent the tying run. … Chris Tillman's seven-inning start Sunday in which he didn't allow a walk or a strikeout is the sixth time in club history that has happened. The others: Jimmy Key (1997), Jeff Ballard (twice in 1989), Rudy May (1977) and Jack Fisher (1961). … Sunday was the first time Orioles pitchers did not record a strikeout since May 27, 2010 against the Oakland Athletics. … The Orioles are 10-12 in series finales this season.
Baltimore Sun reporter Alejandro Zuniga contributed to this article.