BALTIMORE - Jason Hammel, who hasn't faced a big-league team in nearly a month, probably wasn't the conventional choice to start today's American League Division Series opener against the New York Yankees.

Similarly, Joe Saunders, 0-6 lifetime at Rangers Ballpark, wasn't the conventional choice to start Friday's Wild Card game against the Texas Rangers.

But, then, the Baltimore Orioles have defied expectations since April, winning 93 regular-season games and making the postseason for the first time since 1997 after 14 consecutive losing seasons.

"Obviously, we were supposed to finish last. That didn't happen," said Hammel, who will be wearing a knee brace today. "We weren't supposed to get to the playoffs. That didn't happen.

"It's come to an expectation for us. Somebody's going to get it done, and every night it's somebody different. We're very confident in ourselves."

The Orioles' ace over the first half of the season, Hammel (8-6, 3.43 ERA) had knee surgery in July. He returned in September to make a pair of starts, but went back on the shelf with more knee soreness. Initially almost inconsolable about reinjuring his knee, Hammel patiently waited for it to improve. He threw some 85 pitches Monday in a simulated game in Sarasota, Fla., and then another 45 or so in a bullpen session on Friday in Texas.

"No concern with the knee," said Hammel, who called it an honor to get the ball in Baltimore's first home playoff game in 15 years.

Speaking before a workout in Camden Yards on Saturday, Orioles catcher Matt Wieters also sounded unconcerned about Hammel, even though his only starts since July came on Sept. 6 and Sept. 11.

"When he had his time off and came back for his two starts his stuff was right there," Wieters said. "I know his knee feels good. When he gets out there that competitive spirit's going to get going. He'll be fine."

Orioles manager Buck Showalter got the feeling Hammel would be fine when saw the right-hander celebrating after Friday's 5-1 Wild Card win over the Rangers.

"I was watching 'Ham' jump around on the mound. I was going, 'Jeez, he looks pretty good,'" said Showalter, noting how eager Hammel has been to get back on the mound. "He's been champing at the bit. It's been difficult for him because he's been such a big contributor for us."

Like most of the Orioles, Hammel has little postseason experience. He has made one previous postseason start, however, giving up four runs in 3 2-3 innings in 2009 while with the Colorado Rockies.

"I got the first one out of the way," Hammel said.

He will be opposed Yankees ace CC Sabathia, a former Cy Young Award winner who has made 16 postseason starts. Sabathia (15-6, 3.83) has four previous wins in the ALDS, but went 0-2 with a 6.38 ERA against the Orioles in 2012. Previously, however, he dominated the Orioles. His lifetime mark against them is 16-4.

Sabathia was asked Saturday what has changed for the Orioles after so many down years.

"Why are they here? I mean, it's a good team," he said, mentioning Wieters, Adam Jones and Mark Reynolds by name. "They've just gotten a bunch of talented guys that have gotten a lot better and they've made it tough on me."

Yankees manager Joe Girardi, New York's catcher the last time the Orioles and Yankees met in the postseason, concurred with Sabathia and noted the major reason the team went 29-9 in one-run games, never losing when leading after seven innings.

"I think their pitching improved, I think position players improved here," Girardi said. "You look at what their bullpen did and how they changed - the games that you're supposed to win, they won. Last year that wasn't always the case."

While the Orioles insist they are not simply "happy to be here," there's no question they're happy to be back home playing a playoff game at Camden Yards in front of a fan base that took a while to catch on but provided tremendous support over the final weeks of the season.

"Regardless of the outcome, there's going to be a real nice feeling to sharing in what the fans are feeling," Showalter said.

Jim Thome is the only Oriole who has ever played a postseason game in Camden Yards, having helped the Indians beat the Orioles in the 1997 American League Championship Series. For the Yankees, Derek Jeter was around in 1996 when New York - aided by young fan Jeffrey Maier - beat the Orioles in the ALCS.

Game Two is also slated for Baltimore, on Monday night, and Showalter indicated that Wei-Yin Chen would start. Andy Pettitte is set to pitch for New York. But Showalter said things could change in the rotation and in the ALDS roster if today's game is rained out. The remaining games of the five-game set will be played at Yankee Stadium.

Predicted by most to bring up the rear of the AL East, just as they did in 2011 with a 69-93 record, the Orioles are hoping to continue defying expectations in this series. They'll be counting on Hammel to get them off to a good start. He said he'll be ready to go and he knows today is about more than just his return to the mound after a lengthy break.

"This is a big opportunity for a lot of guys," he said. "I'm not focusing on what I've done or what I need to do. It's more or less go out there and just continue to do what we as a group, as the Orioles have been doing all year."