Baltimore and Washington are poised to wrap up their respective division titles this week and that could come as soon as tomorrow.

The Orioles have a magic number of three to clinch the AL East heading into the start of their home series with second-place Toronto tonight. The Nationals' magic number is four for clinching the NL East. They travel to Atlanta for the start of a series with the second place Braves.

The Angels are also well positioned to clinch this week. Their magic number for wrapping up the AL West is four heading into the start of their home series with Seattle. The Mariners have something to play for. They're locked in a tight battle for one of the NL wild cards, trailing by one game heading into tonight's play.

Max Scherzer goes for win No. 17 tonight when the AL Central-leading Tigers face off against the Twins. Detroit has a game-and-a-half lead over second-place Kansas City, which is home to the White Sox. James Shields goes for his 15th win for the Royals. He takes a career-high 18-and-a-third-inning scoreless streak into the start.

After dropping two of three to the NL West-leading Dodgers, San Francisco travels to Arizona to try to regroup. The Giants are three games out of first, but still hold one of the two wildcard spots.

Los Angeles opens a series at Colorado.

There are six games each in the American and National Leagues.

More From ESPN Western Colorado