BALTIMORE -- Mickey Jannis, a 33-year-old knuckleball pitcher, finally got his big league moment. The third-oldest rookie in Orioles history tossed 3 1/3 innings in the series finale against the Astros in the 13-0 loss at Oriole Park at Camden Yards on Wednesday night.

Since being drafted in the 44th round of the 2010 MLB Draft, Jannis spent time with both the Rays and Mets organizations and played in independent leagues and overseas before signing with the O’s in free agency in '20.

“The dedication he has to the game and the grind, and for him to get an opportunity up here, it speaks volumes to his character and his perseverance,” said Orioles starter Thomas Eshelman, who allowed six runs in his second start of the season. “So I was happy for him to get an opportunity up here.”

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With an entire fan section made up of family and friends chanting his name and cheering him on in the fifth, sixth, seventh and eighth innings, Jannis hoped to keep the O’s deficit to six runs.

“He is a professional,” said catcher Austin Wynns on Jannis’ outing. “He's paid his dues. He went out there and competed. And that's all you can ask for a guy like him.”

The righty tossed a scoreless fifth inning, striking out Yordan Alvarez -- the first batter he faced. A flyout, a walk and a caught stealing would end the inning for Jannis, who threw just 13 pitches in the frame.

When the sixth came around, Jannis would face a very hot top of the Astros’ order, including Jose Altuve and Michael Brantley. After allowing a single to Martín Maldonado and issuing a free pass to Altuve, Jannis tossed a knuckleball to the inside of the plate that Brantley smacked for an RBI single.

“Sometimes [the ball dances] and sometimes it [doesn’t],” said Wynns of Jannis’ struggles when facing the Astros’ lineup for the second time. “And you know what? That's what knuckleballers do, you know? I'm happy for the man, and I'm happy he's here and [hopefully he has] a better outcome next time.”

Alvarez must have gotten a good look at the knuckleballer’s stuff the first time around since he smacked a 448-foot homer with an exit velocity of 112 mph in the top of the seventh. The second homer of the inning was a three-run shot to left-center from Abraham Toro.

“By being able to go into the eighth inning, he actually saved us a little bit by me not having to use somebody else, which affects tomorrow and the next day,” said manager Brandon Hyde on the decision to send Jannis out in the eighth, where he allowed an additional three hits and two runs to score. “I never liked leaving somebody out there unnecessarily, but in some cases, you got to think about tomorrow. And with a couple of guys down today, I need help for tomorrow. So we went as long as we could with Mickey.”

The O’s chance of winning was slim well before Jannis allowed seven runs over 3 1/3 innings. Baltimore was held to just six hits in its fifth shutout loss of the season.

“It’s a mix of both,” said Wynns when asked if the quality of opposing pitching or the team's approach was something that could be improved upon after its ninth sweep of the season. “Obviously [you try to] have quality at-bats. They have a really good staff. I mean, tip your hat, they have a good staff. So we just got to be better. We got to get better.”