Whereas the National League is more crowded and full of teams that could be ripe for an upset come October, the American League is far more top-heavy. The Wild Card race has essentially narrowed to four teams, and one of those will end up winning the AL Central, anyway.

The Astros and the Yankees have emerged as the clear favorites in the American League, and a potential ALCS between the two clubs is a salivating prospect. However, there is a very real possibility that one–if not both–teams could be out in the ALDS.

Let's take a look at the three American League teams that pose the greatest threat to the Houston Astors and the New York Yankees:

Cleveland Indians

The Indians have clearly been one of the best teams in the second half, going 22-10 with a +59 run differential and making consequential moves at the deadline to land both Yasiel Puig and Franmil Reyes (Puig has dominated since moving to Cleveland, while Reyes has really struggled).

They could also become that much more dangerous should Corey Kluber and Carlos Carrasco return to the starting rotation. Kluber sometimes ran out of gas in October, but he should be fresh and ready for action should he return fully healthy.

Say the Indians manage to win the division. Regardless of whether they play the Astros or the Yankees, they are going to pose a major threat. Cleveland has two top-end starters in Mike Clevinger and Shane Bieber, and they have one of the deepest bullpen units in baseball.

Not to mention, they are far more dangerous offensively, especially with Jose Ramirez finding himself in the batter's box. Ramirez is slashing .320/.346/.680 in the second half, and forms a powerful trio at the top of the lineup with Francisco Lindor and Carlos Santana.

Throw in Puig and Reyes (should he get adjusted to playing in Cleveland), and you have five different guys who are very capable run-producers. Do not forget about Oscar Mercado, Tyler Naquin or Jordan Luplow (currently on IL) either. They have all shown serious improvement in the second half.

The Indians have been the best team in baseball since the start if June. Having made very tangible improvements at the deadline and also knowing that there is a possibility to add two more experienced starters to the rotation, they are extremely dangerous.

Make no mistake, the Indians could be a sleeper to reach (and win) the World Series.

Minnesota Twins

The Twins are essentially the inverse of the Indians. Whereas the X-factor for Cleveland is likely to be the offense, the X-factor for the Twins is certainly the pitching staff.

Minnesota ranks third in baseball with a 114 wRC+, and they also rank third in runs scored. Nelson Cruz is having arguably his best season as a pro, and Max Kepler is one of the most underrated outfielders in the game. Once Byron Buxton returns, this lineup could be one of the deepest in baseball entering the playoffs.

However, the Twins need to improve on the mound. Luckily, it appears they are already making strides in this regard. Jake Odorizzi has been excellent in each of his last three starts, and Martin Perez was excellent on Tuesday (though he has struggled since the break).

Minnesota elected not to add a starting pitcher at the deadline, so guys like Odorizzi and Jose Berrios need to show that they can consistently pitch like frontline guys and anchor the rotation.

The jury is still out on the bullpen as well, especially until after we have seen how Sam Dyson looks following a stint on the IL. However, Sergio Romo was an excellent addition, and Taylor Rogers has been one of the best closers in baseball this season.

Ultimately, the Twins are going to be tough competition because of their offensive firepower. They likely stand a better chance of defeating the Yankees (weak and injury-riddled rotation) than the Astros, but maybe they score a bunch of runs and get good performances from Berrios and Odorizzi in the first two games, essentially putting a stranglehold on either series.

Tampa Bay Rays

The Rays are really going to struggle to hang on to a playoff spot given all of their injuries, but if they do? The Yankees and Astros could be in serious trouble. Yes, the Rays rank just ninth in the American League in runs scored, but they still have the fifth-best run differential in all of baseball.

Charlie Morton might be the strongest candidate to win the AL Cy Young Award, going 13-4 with a 2.90 ERA , 11.1 K/9 and 2.78 FIP through his first 25 starts. Yonny Chirinos as proving to be an effective starter before he just recently hit the IL, and Ryan Yarbrough has been spectacularly underrated.

So imagine if the Rays get Chirinos, Blake Snell and Tyler Glasnow back and in form before the start of the playoffs. They would have perhaps the deepest rotation of any American League team.

As far as the offense goes, both Eric Sogard and Jesus Aguilar are already looking like major contributors. Sogard has three homers and a 1.210 OPS in his first 12 games with Tampa Bay, while Aguilar is hitting over .400. Tommy Pham has been terrific when healthy, and the same goes for Austin Meadows and Brandon Lowe.

Tampa Bay struggled a bit in June and July, but a 9-2 start to August likely has them feeling like an elite contender in the American League. If the bulk of rotation is healthy, Sogard and Aguilar could make the difference in giving the Rays more than just a fighting chance against the Astros or Yankees.