Dana Eveland and Tsusyoshi Wada, who started against the Twins on Tuesday, are the other lefties still in camp, although they could be starting candidates with Alfredo Simon.
Further complicating matters is the fact that Simon, Eveland and Patton are three of the Orioles' 10 players who are out of options this spring, meaning they would each have to clear waivers to remain in the organization if they don't make the team.
"It's really tough to work on things, because I don't have the luxury to give up a couple runs here or there and not worry about it," Patton said of the spring competition. "I feel like I have to put up a zero every time. I've been pitching more like it's in-season.
"The game means a lot every time. So I am mixing in more pitches. I am not trying to work on things that are bad. I haven't really improved from outing to outing. But I have found a way to persevere and get outs when I haven't been pitching great. I know I can pitch better, but for the outcomes, I feel like I have competed and gotten zeroes."
The makeup of the bullpen is one of the biggest remaining question marks and is largely a function of what they do with the rotation, namely the final spot behind Jake Arrieta, Wei-Yin Chen, Jason Hammel and Tommy Hunter.
The Orioles seem to have five relief spots accounted for in right-handers Kevin Gregg, Jim Johnson, Luis Ayala, Matt Lindstrom and Pedro Strop. Assuming they go with a 12-man staff to start, the Orioles would presumably need a long reliever and a lefty. Simon, Eveland and Wada right now are candidates to be long men or starters, a decision that will have ramifications on where Patton fits in. Sidearmers Darren O'Day and Pat Neshek are also in the mix.
"You understand, I don't call it the dilemma, but the good challenge we have," manager Buck Showalter said of putting together the Opening Day bullpen. "We didn't have this challenge last year. We have good pitchers that are available to pick from. We try not to get involved [with who has options and who doesn't]. You understand if it's 50-50 what the tiebreaker might be. But, in a lot of cases it's not in our mind."
Patton was the Houston Astros' ninth-round selection in the 2004 First-Year Player Draft and came to Baltimore as part of a five-player deal for Miguel Tejada in December 2007. After starting last season in Triple-A Norfolk, the 26-year-old Patton was recalled for good July 17 and went 2-1 with a 3.00 ERA in 20 games, including a 0.77 ERA in eight September outings.
"He's not here at this stage because he's out of options," Showalter said of Patton. "He's here because of what he showed us from a health standpoint last year and the ability to get people out in a good environment to judge in.
"He's shown us that he's still healthy and still able to do what he did last year."