As the final week of baseball's regular season begins much of the focus will be in the American League with three post-season spots still available.

Starting play today, Oakland and Kansas City are on top in the AL's wild card race. Seattle is 1 1/2 games out. Detroit leads the AL Central by 1 1/2 games over Kansas City. The Royals will first complete a suspended game at Cleveland today, then play the regularly scheduled contest. The Tigers open a series home to the Chicago White Sox, Seattle visits Toronto while the A's host the Los Angeles Angels.

The New York Yankees haven't quite been eliminated from playoff contention yet, but it certainly looks like Derek Jeter's final games are upon us. The Yankees wrap up their regular-season home schedule with a four-game series against Baltimore starting tonight, then head to Boston for three more at Fenway Park.

The other AL game tonight has Houston at Texas.

Over in the National League, if the season ended today, San Francisco and Pittsburgh would be the two wild cards, and with Milwaukee 4 1/2 games behind them, the Giants and Pirates appear headed to the postseason.

The main source of uncertainty is the NL Central race, where Pittsburgh could still conceivably catch first-place St. Louis. The Cardinals send Adam Wainwright to the hill against the Cubs in Chicago tonight. Wainwright is looking for his 20th win of the season, with a 19-9 mark.

The Pirates visit struggling Atlanta. The Braves have lost three straight and 8 of the last 10.

The Giants, who begin the night 4 1/2 games behind first place Los Angeles in the NL West, visit the playoff bound Dodgers.

The other NL game tonight has Colorado at San Diego.

More From ESPN Western Colorado