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If this is Bud Norris' last start with the Houston Astros, he will at least have a chance to give his club a first.

Norris and the Astros look for their first ever victory in Baltimore as they begin a three-game series with the Orioles on Tuesday night.

Currently 34 games under .500 and 27 games out of first place in the AL West, the Astros are expected to be major sellers ahead of Wednesday's non-waiver trade deadline. They got things started on Monday, sending closer Jose Veras to the Detroit Tigers for minor league outfielder Danry Vasquez and a player to be named later.

Among those dealt by the Astros ahead of the trade deadline over the past few seasons include Carlos Lee, Brett Myers, Wandy Rodriguez in 2012, Hunter Pence and Michael Bourn in 2011 and Roy Oswalt and Lance Berkman in 2010.

Norris could join that list given his expected pay raise next season. He has been Houston's top starter all season, going 6-9 with a 3.93 earned run average in 21 outings, but is winless in his past three with an 8.47 ERA.

The right-hander gave up 13 runs, 17 hits and three homers over back-to-back losses prior to a no-decision versus Oakland on Wednesday. In his 13th quality start of the campaign, Norris allowed three runs on four hits and three walks over 6 1/3 innings while striking out seven.

"I felt like Bud was outstanding," said Astros manager Bo Porter. "His slider was unbelievably sharp; great command of his fastball in and out. He battled and pitched like a No. 1 starter."

Norris afterwards accepted the fact that it could have been his last start with Houston, which made him a sixth-round draft pick in 2006.

"It's something I've prepared myself for last night and the days leading up to it," Norris told Houston's website "It's definitely a little emotional, too. I just went out there and threw the best ballgame I could and give my team a chance to win.

"It's a challenge for sure. There's a lot going on, but you have to go out there and keep your focus and just go out there, play the game and pitch."

The 28-year-old Norris faced the Orioles for the first time in his career on June 6 at home and picked up a 3-1 home loss, giving up all three runs and fanning seven over seven innings.

That win by Baltimore came in the rubber match of a three-game series and gave the Orioles a victory in eight of the past nine meetings between the clubs. Baltimore has never lost at home versus Houston, winning all six matchups.

The O's hope that trend continues as they were shut out 5-0 by the Boston Red Sox on Sunday, their fifth loss in six games. That leaves Baltimore five games out of first place in the AL East and just a half-game ahead of the Cleveland Indians for the league's second wild card.

"We're grinding right now, not going too hot," said Sunday's losing pitcher for Baltimore, Jason Hammel. "We're still playing close ball games. It's not like we're getting blown out."

Looking to get the Orioles on track tonight will be Wei-Yin Chen in his first ever meeting with the Astros. He was on the disabled list during the last meeting, part of a near two-month stint caused by a right oblique strain.

Chen is 2-0 with a 2.18 ERA in three starts since his return and has not lost since May 1. He has won three straight outings before not factoring into a 4-3 loss at Kansas City on Wednesday.

The 28-year-old southpaw yielded three runs over 7 1/3 innings and was touched for two homers, the first he allowed in five starts.

Chen is 5-3 with a 2.78 ERA in 11 starts this season, going 2-0 with a 1.86 ERA in three at home.

The Astros, who have lost 10 of 12 and 20 of their past 25, hope to have second baseman Jose Altuve in the lineup after a tight left quad held him out of Sunday's 2-1 loss in Toronto. He is hitting .280 in 97 games this season.