LEADING OFF: Big games in DC, Toronto and Houston

A look at what's happening around the major leagues Tuesday:

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BELTWAY SERIES

The Orioles and Nationals try to get in the opener of their interleague series after rain washed out Monday's game. Ubaldo Jimenez, starts for Baltimore, which entered 5 1-2 games back in the AL wild-card race. Gio Gonzalez follows up a start in which he struck out a career-high 12. Washington trailed the Mets by six games at start of Monday.

NOTHERN EXPOSURE

The Yankees turn to rookie Luis Severino (4-3) as they try to catch the Blue Jays atop the AL East. Host Toronto sends Marco Estrada to the mound. The right-hander pitched eight scoreless innings in his last outing.

TAKE TWO

Cubs righty Jake Arrieta goes for his 20th win - again - when he faces Milwaukee. He pitched well in his previous outing but did not get a decision. Arrieta is better in the road, going 12-1 with a 1.68 ERA, but his stats at Wrigley are pretty impressive, too. He has a 2.33 ERA in 13 starts at home.

ROOKIE IN RACE

Houston rookie Lance McCullers starts against the Angles in a matchup of two teams fighting for a playoff spot. McCullers limited Los Angeles to two runs in five inning on Sept 12. Hector Santiago starts for the Angels after throwing just 30 pitches in his previous outing, his shortest this season.

ACE OF THE CARDS

Cardinals right-hander John Lackey, on a stellar run in which he has not thrown fewer than six innings in 18 starts, will be tossing to a different catcher when he faces the Reds. Yadier Molina was diagnosed Monday with a torn left thumb ligament. The injury was not as severe as feared and St. Louis hopes their All-Star will return before the end of the season.